I've been a little interested in graffiti lately. It's not just something that's usually done illegally on train cars and the sides of buildings. It's a rebellious form of free expression. It's a way to make your mark in a world where you can be easily looked over.
At the risk of getting deep in a really annoying way, I think a lot of things we do in this life are graffiti. We don't all paint walls, but most of us find some rebellious way to make our mark on the world. If you don't, I suggest you find something. A little rebellion, especially when it's not against the law, is totally healthy and will make you smile every time you think about it.