Yeah, this happens to me all the time. I've managed to suss out a number of the factors for me, but based on everything else I've read on it, I've also learned that the factors, reasons, and responses are different for different people.<p>So, the short of it is, you'll have to figure this one out on your own, by figuring yourself out.<p>Here are some of the things that cause me to get lazy, and how I handle them:<p>1. Probably closest to what's going on for you, I will occasionally be working on a project and then hit a problem that I wasn't anticipating. It seems like my motivation goes through the basement, but what's actually going on is that I'm just chewing on the problem, turning it over and over in my head. Eventually -- days, weeks, or months, depending on the problem -- I will find the extra insight or information I needed and the whole thing will fall together. I try not to stress out over this any more; if the project doesn't have a deadline, then I let it stall more-or-less indefinitely. If it does have a deadline, I try to adjust the deadline accordingly. If I can't adjust the deadline, or it just really needs to get done, then I try to work around the roadblock by implementing a "good enough" solution. I have trouble working on project steps out-of-order, so even if I don't <i>have</i> to solve a particular problem in some project before proceeding, the project will still usually stall.<p>2. I've lost interest. In this case, the best thing is just to come to terms with giving up on the project, and I do this by realizing that there are many projects that I would actually be interested in working on, and there's no reason to beat myself up over something I don't care about.<p>3. I'm exhausted. The best thing to do here is go out and eat a good meal (I don't tend to cook very well), go for a walk, read a book, re-connect with some friends, and take a nap or get a full night's sleep.