For me it's about that dopamine hit whenever I finish a feature. When I'm finally testing a new feature or functionality I've been working on I get an immense dopamine rush, likewise if a feature is taking me too long to finish it's much the opposite feeling. I don't really get this working on work projects because there's inevitably rules I have to follow. On my side project though it's something about having access to the entire plane (frontend, backend, DB, etc) that gets me excited, because I know there is no blocker that I have to rely on others to solve.<p>There's something something intoxicating about working on a large side project knowing that you're in absolute control, if I see a bug, any bug, I have the power there and then to fix it, no asking permission or working with other teams.<p>Then there's also the financial motive, I get the chances are minuscule but there's something so incredibly intoxicating and sexy about knowing that there is a non-zero chance that the project I'm working on may one day make me a multi-millionaire or a billionaire. It's a bit like walking into a casino and knowing that any slot you pull the lever on may spit out a jackpot. The rational part of my brain knows to keep my expectations in check, but I do let the "lizard" part of my brain out once in a while to daydream about what yacht or jet I'm getting once my side project IPO's