One of the most satisfying things about doing engineering work is that moment when you finally come up with a solution to a problem you've been stuck with for a while. (Coding something up that inexplicably works the first time without any problems whatsoever is just as magnificent, but it's not extremely common.) Recently I've found, though, that I get a very similar feeling from the fiction writing that I've been doing. Since I hadn't really written fiction in the last twenty years before now I wasn't expecting it, but I've discovered that the sensation I get when I have a plot hole and finally find a creative and interesting way to resolve it is actually very similarly euphoric.
I'm writing and designing a game. I originally thought that I'd be spending most of my time on designing the game mechanics, but I've actually spent considerably more time on the creative writing portion so far. Part of that is because it's easy to get little bits of creative inspiration at random times throughout the day. (Usually this is inconvenient, because so far most of these have happened either while I'm in the shower, or at about 2:00am.) But I think that part of it is just because it's very rewarding. I get bursts of exciting, incremental reward in my brain just for coming up with creative plot solutions. The game mechanics aren't as fleshed-out as the story is at this point, but I don't know if I'll get the same level of reward for every little change I make that makes the gameplay better.
I'm finding that OneNote is particularly excellent for keeping track of a creative writing project. Since bits of inspiration come at any time, I want to be able to jot them down wherever I am, whether that's at my computer or on my phone. OneNote will then sync anything I type between all of my devices, so I have all of my story outline notes everywhere I go, so I don't have to keep a paper journal or little scraps of sticky notes or anything like that.