I really like sharing knowledge with others, and that's what this website is mostly about (with the exception of a rant here and there, when I need to vent some...).
So, whenever I manage to create something that doesn't just fulfil my needs but also works for somebody else, I gain a fair bit of happiness (quite important for an otherwise extremely unsocial introvert like me).
Here's an example: I created my Sun to PS/2 keyboard converter because I needed something like it, and since posting my solution here I've heard from a few others who have built my contraption successfully. The most recent of those who reported back, Edward Robbins, has a subtly different model Sun keyboard and it took us a few email exchanges and experiments to determine how the one (undocumented) extra key on his keyboard could be made to work - but we got there.
Without the net he and I would never have gotten in touch, let alone ended up benefiting mutually from each other's efforts.