I love the lyrics to "Fight Test" by the Flaming Lips. I won't put them all here, but it starts like so:
"I thought I was smart - I thought I was right
I thought it better not to fight - I thought there was a
Virtue in always being cool - so when it came time to
Fight I thought I'll just step aside and that time would
Prove you wrong and that you would be the fool -"
And as the song goes on, it kind of tells a story about discovering that some things are worth fighting for, and there isn't always a virtue in being cool.
I like it because it speaks to how you grow up after you grow up. You stop being a child, but it takes a long time to learn that it's not really about being cool.
Of course, there's a double meaning to "cool" in the song: cool as in adolescent cool, and cool as in not getting worked up and fighting.
And the irony, of course, is that when you stop being cool and seeing cool as so important, that's when you really start to be cool, inside and out.