I have defeated a piece of legacy code that's been causing me problems for the last 4 hours or so, eventually tracking down a bug -- or in this case, a missing method call that was instead defaulting back to the parent class's non-functional version -- and fixing it, making both my project work and the legacy code stronger, faster, better.
I'm a bit mentally worn, but damn it feels good to be me right now. This is why they pay me the big bucks, right?