Humour is pure

Tony suffers so much, and is sarcastic almost always. However, it's really this that allows him to connect with people. He's not just using humour as a shield to deflect any emotions. In the beginning he is, but we start seeing how humour can be used to cope, to actually deal with our issues. It gives us a different way to view the world, one not only tainted by malevolence and pain. It is so simple, yet so joyous to watch Tony share a laugh about something that actually hurts him so much.