My "side project" actually pays the bills yet I'm not sure if my wife will ever fully understand that, despite it technically being "work" (and despite some rare complaints/bad days, like anything else), I actually thrive off of the challenges and sincerely enjoy it. And so working >8 hours on it isn't just because I "have" to, it's often because the challenge is so fun & thrilling that I _want_ to.

Of course, balance is important and I won't try to fool anyone -- it's something I'll likely always be working to improve.