You can't do that

Surprisingly enough, this can even happen in academic environments that should know better.<p>Though far from the level of difficulty presented by jacquesm, the same thing happened to me with an end-of-term project a few years back.<p>We had to make a small piece of software in Java. Most of my mates were going for boring stuff, such as sudoku solvers or small neural networks to play the likes of Connect four.<p>I wanted to make a Gameboy emulator.<p>"You can't do this", said my professor. "At least not in two weeks' time."<p>Well I don't remember much besides coding during those two weeks, but guess what - after 14 days, my program could boot Tetris. No sound, granted, but it was playable.<p>My professor was quite the sore loser though - he considered the program incomplete since it only booted a few roms, didn't have sound and could crash randomly. I ended up turning in a gameboy rom dissassembler instead, complete with GUI and breakpoints setting.<p>Still, never believe that "you can't do that".

<i>And in my experience when enough people are saying that 'you can't do that' there is an opportunity waiting for you that is proportional in pay-off to the number of people asserting that it can't be done.</i><p>Great thought.<p>Most of my most memorable successes were when others said that something couldn't be done. First you think, "Why not?" Then you think, "What would it take?" Then you figure that you'll never find out for sure unless you try. The reward is compounded by the initial skeptism.<p>Just a few silly examples (any of these sound familiar?):<p><pre><code> Manager: Shop Floor Control is impossible. Me: Why? Manager: Because the base data is so inaccurate. Me: So? Manager: It would take years to fix all the data. Me: What if we turned in on anyway? Manager: The output would be worthless. Me: Wouldn't it show where the base data was inaccurate? Manager: Yes. Me: Then you could fix the biggest culprits? Manager: I suppose. Me: So turning it on would expedite data fixing? Manager: Yes. Me: So it's not really impossible? Manager: Well... Manager: Bug free software is impossible. Me: What would it take to make is possible? Manager: Nothing. Can't be done. Me: What if we added systems testing to unit testing? Me: And then built rigorous test plans covering almost everything? Me: And then enforced User Acceptance Testing? Me: And allowed nothing into production without passing? Me: Would it be better? Manager: Yes, but we can't afford to do all of that. Me: So, bug-free software isn't impossible, just expensive? Manager: No, it's impossible. Get back to work. Me: Sigh. Manager: A web app is impossible. Me: Why? Manager: Because it depends upon data entered by regular people. Me: So? Manager: People are idiots. They enter wrong data all the time. Me: What if we trained them? Manager: Impossible. They don't work for us. Me: What if we made the software smarter? Manager: What do you mean? Me: Data validation. Me: Data reasonableness based upon rules or history. Me: Crowdsourcing data validation. Manager: The data would still be bad. Me: What would it take to make the data good? Manager: Nothing. Impossible. Me: Sigh.</code></pre>

<i>"In the end the project led nowhere, apparently there was a patent that it violated (of all things, one that had to do with the codes on laundry for hotels and hospitals held by Philips) but that by itself had nothing to do with the technology or whether it was possible to build this."</i><p>Hurray for the patent system supporting innovation.

"Let your limits be determined by physics and other real world constraints, not by the lack of imagination or (wrong) knowledge of others."<p>Awesome takeaway! Without people taking that attitude, we probably would still be living in caves.

I hate to say it, but the question "It's impossible?" is my kryptonite--but in the opposite perspective.<p>I accidentally established myself as a capable and competent worker at my job and have unfortunately given management the confidence that I can do anything. I'm using a negative context here because I've lost the ability to say no to them. I suppose since my job as a programmer is to give them what they want I should never want to say no, but I'm a sucker for elegance and I really try to avoid solutions that are overly complex and convoluted. Unfortunately, there are occasions in which a feature requirement requires such a solution. Or rather, not the actual feature requirement, just one of the "tweaks" they like to nitpick on to make it perfect. I.e "This is great, but you know what would make it perfect?" syndrome. Usually, I'm fine with these but when the tweak requires a complete overhaul or reimplementation--potentially days worth of coding to implement I'll try to dissuade them from it. Inevitably, if it's something they are really stubborn on when I say "well, I can't really do that--the system doesn't support event callbacks which is what would be required to implement...." I'll get back "It's impossible?".<p>And thats it, cat's got my tongue. I want to say yes. So bad. But I know the answer is no. I know they are confident in my ability, so they think they know the answer is no. But, seriously I'm gonna have to write a third party application in a different language and write a service protocol to communicate between the main ERP suite and the third party app to accomplish this and it's just so they can get an extra description feedback to an auto-complete feature. I know there are more important, more critical, more exciting issues that I could and I think I should work on. Whats worse, is that if I were a little less proficient, if I knew one less programming language it would impossible for me. Then again, it still wouldn't because I know I could just learn that one language and it would be possible. Arrrggghh there's no way out of this question.<p>"Well, no it's not impossible. I can probably do it. But it's going to take an extra couple of days.."<p>"Okay, let me know when its done."<p>[grit teeth].

One of the best problem-solving strategies I was ever taught was to respond to things like this with "well, what if it wasn't?" Don't try and fight their reasoning about why it's impossible, because you won't win - instead, step around it by getting them to ignore the part they're/you're getting stuck up on.<p>It takes a bit of persistence and convincing the other party to engage in what they consider a flight of mental fancy, but once you get over the "impossible" part and start figuring out how to solve the rest of the problem, I find that a solution that avoids the initially-impossible part tends to present itself. That, or you'll figure out why what you thought was impossible isn't. The beauty of this is that it works equally well when you're trying to convince someone else of something you know to be right and when you're trying to figure out a solution yourself.<p>The other easy strategy I use all the time (and this is more for concrete problems, as opposed to intellectual/theoretical ones) is start by deciding if the problem is one that can easily be solved by throwing money at it. If it can be, then it's a much easier question - you just have to determine if the problem is worth the money it would cost to fix it, which is simpler. If the problem can't be solved with money, then you know where to start to find a solution (enumerating all the non-monetary resources you have and seeing what might work).

This shows one of the reasons I love math: mathematicians only say "you can't do that" when they can prove you can't, otherwise they'll say "I don't see how to do it and it would be hard because ..."

Great article. Whenever someone's usually said that to me, my first thought is usually, "Why not?".<p>From the other end, in my experiences, hearing "you can't do that" in a corporate setting has often (not always) meant that the manager/company didn't feel it worth the risk to the company. The manager won't be around 2 years from now when your project is completed, so he would rather you work on things with immediate impact so it benefits his review. Because of this big companies often get very risk averse, focusing on big, cash-cow projects and consequently slow their innovation.<p>Contrast that to startups where you've got a bit more freedom, I'd think you're less likely to hear it (if so, it might mean more of "we don't have the resources/money"). I think it's often less of the person being an ass, and more about what they're incentivized to promote.

If someone says: "That’s impossible;" You should understand it as: "According to my very limited experience and narrow understanding of reality, that’s very unlikely."<p>- Paul Buchheit

I find that the "You can't do that" is often said by people who just don't want to bother.<p>I was recently working in a company where the task tracking system wasn't linked in any way to source control. I thought linking the two would be a great gain: being able to see the modified files from the task management system, and resolving the task directly in the commit message would allow managers and developers to easily increase productivity, if only by a little bit.<p>I had to have 3 different meetings with the sysadmin to get him to do that, each one escalating further up in the company hierarchy. Eventually, we had to tell him exactly how to do it, and my boss said it had to be done. The main reason the sysadmin said he did not want to do it was that he felt there would be no gain.<p>I learned a lot about office politics then...

Some circumstances warrant "there is a theorem stating that what you want is not possible."

This is a motivational article, which is fine. Some people (depending on their personality and their current state in life) need motivation: 'you can do that'!<p>Some other people, the born dreamers who are overly motivated and naive by default need experience, need to fail a lot to learn that some things are harder than it seems. (I am more in this category.)<p>But in reality there is a market for the belief of whether 'they can do that': (angel) investing. If someone bets that people's capabilities are undervalued she should buy into the market (invest in early stage enterpreneurs). If someone bets that people's capabilities are overvalued she should sell (not invest).<p>Saying 'you can do that' is cheap. If you really trust he/she can do that you invest. I think the market is balanced in Silicon Valley (some say overvalued) and undervalued in some countires where there is virtually no angel investing in technology startups at all. (Like where I live in Eastern Europe.)

In a similar vein....I am presently working in more of a business analyst / advanced end user for a product under development. I don't know how many times I've been told by developers on the project that something "can't be done". Some good fun was had for the first few weeks before they found out I was a developer, after a few times of sending them the code to accomplish "the impossible". But now it's just getting annoying...they <i>still</i> regularly fall back on the "can't be done" crutch, even when I tell them otherwise. Absolutely zero curiousity in learning something new....yet their considerable egos seem to remain fully intact.

Good advice. Generally when I give feedback on an idea or proposal that is not possible to implement I try to give it as "I see the following challenges, ... " and try to outline my reasoning for problems for which I am not aware of a solution to. If you come back with credible ways to attack those issues I'm all for it.<p>Its a big demotivator if you feel like you are being dismissed out of hand. So if you're managing a team or have folks coming to you with new ideas, 'you can't do that' is probably the worst thing you can say to them.

A coworker of mine shared an experience she had in college a while back.<p>Many years ago, for a course project, she proposed software that would allow you to tag songs and get information about it. Perfect for identifying that obscure song at a bar. The professor told her, flat out, it was impossible. He explained his reasoning and then suggested she work on another project.<p>All of this came to light when I showed her Shazam. Her first words were "I KNEW IT WAS POSSIBLE!"

Personally, someone saying to me "You can't do that" is a great motivator. "You cannot get A+ in that class, it's impossible." == me studying way harder (and finally achieving that A). In fact, ironically, I always tend to do better when people think something is really hard.. maybe because I'd take it more seriously.

You know what, that card IDing idea is awesome. What sort if douchebag says 'you can't do that?' My reaction would be positive/excitement and a desire to contribute, but it seems there's just this large subset of people out there who react to every new suggestion with total stick-in-the-mud negativity. Like it's their natural, gut-instinct. Maybe they just never see ideas (like the card reader) as these wonderful elegant things, or they can't imagine enough about the rest of the problem domain to see it's potential value, who knows.<p>At my first job my whole team had to enter details on a shared spreadsheet. I suggested we set up data-validation or drop down menus for input, someone straight off said 'can't be done - someone tried it last year, didn't work.' then took me like two weeks of campaigning just to overcome this initial knock back. What a waste of time.

For many years I would bounce my ideas off of people, and they would look at me like I was delusional. This made me think I was delusional. After working on my MVP for the past 3 years, I have finally figured out that the best ideas are the ones that people say can't be done. With enough time and dedication anything is possible. Disregard the naysayers and keep on truckin'.

I feel it is always wise to take the word "impossible" as a personal challenge to prove otherwise.

I keep telling my kid, the worse bad words out of all of them are "can't" and "never".

In sum the difference between 'Unlikely' and 'Impossible' is crucial...

Woz didn't know it was impossible: <a href="http://www.youtube.com/watch?v=pyKlNjwR03M#t=7m45s" rel="nofollow">http://www.youtube.com/watch?v=pyKlNjwR03M#t=7m45s</a>

Another favorite of mine: "It's not that simple".<p>More in a social context than a technical one, it usually implies "This is my excuse for not doing it"

I suspect this guy heard 'You can't do that' quite a few times before doing this:<p><a href="http://www.bbc.co.uk/news/world-europe-12773427" rel="nofollow">http://www.bbc.co.uk/news/world-europe-12773427</a>

Free electricity may be a pipe dream, which is understandably dismissed, even IMO (how could you get free energy from nowhere?). But a gizmo which pulls electrical or magnetic energy from the sun or surrounding space by some heretofore unimplemented and unaccepted method is not as much of a pipe dream. However it's just as quickly dismissed by academic physicists as a pipedream even though they don't know what specifically they are dismissing.<p>So I agree! Keep your confidence if you think you've got an idea that may work, especially when there's a bunch of people who have a vested interest in your device not succeeding, telling you that it won't work.

When someone tells me "you can't do that", I usually assume they are against it and want to imply that doing that would be the stupidest thing ever.

The bit about the patent is a little depressing. I wonder how many novel bits of technology were shuttered because some big company had some similar patent that they'll never use outside of lawsuits and as an asset for mergers and acquisitions. "We have the 'read security card with optics' patent. Its worth a lot!" Government mandated monopolies on ideas is just a bad idea.<p>Everytime I think about starting a company or investing in tech, stuff like thinks makes me reconsider.

I think they mean you can't do that because of the patents? Or you can't do that because it was already tried and it went nowhere, as the author found out.

But that's a basic internet manipulation trick.<p>1) Have problem 2) Find related discussion forum 3) Post problem, state or imply it's probably impossible. 4) Get much more interest and better answers than a plain question would have.

"You can't do that" - translation:<p>1. I don't want you to do that because of x,y,z.<p>2. I saw some other people try that, and they failed.<p>3. Someone else doesn't want you to do that.<p>4. I tried it, and I failed at it and my ego is tiny.<p>5. Rule or Law X states you shouldn't do that.<p>Can't is such an abused word, better to not use it at all to make yourself clear.<p>When you understand the laws of physics, anything is possible.

This article is amazing, One of the best parts of being young is you don't have enough experience to know what you're not capable of. As a junior programmer I went down more misguided pathways than I care to remember, but every once in a while one of those misguided pathways had gold at the end, and I got there.

Great article. I read that while imagining it in the voice of Morpheus. ;)