I'm happy today because... I was able to be there for a friend when she needed someone to listen to her problems and cheer her up.
May not seem like a big thing, but all my friends live out-of-town except the one. So I usually can't be there to try and support them, which makes me feel pretty down.
But being able to actually try, and succeed, at helping my friend, leaves us both feeling happy. We just went, wandered around, got energy drinks, all the typical silliness, including belting out some of our favorite tunes.