Just an Innocent Thought or Two

Have you heard Greenday's big song for the year: 'Wake Me Up When September Ends?' I REALLY like it!
For those who may not have heard it, the first lines go like this: "Summer has come and passed. The innocent can never last. Wake me up when September ends."
I listened to the song so much the other day that the words got frozen in my head!
"The innocent can never last. The innocent can never last...
The innocent can never last?"
What do you think about this statement? True? False? Is it happy? Sad? What do you think innocence is?
I've heard a couple other statements that, I would say, have to do with innocence.
In another song I know, the vocalist makes this claim: "All I've ever wanted, are clean hands and a pure heart."
Would you say that's innocence? Is it the desire for innocence? Is she innocent for simply desiring innocence?
What about this statement: "Blessed are the pure in heart, for they shall see God."
If the innocent can never last, does that mean that no one's going to get to see God? Is pureness of heart innocence?

I'm interested in this topic of innocence. Very interested. I want quotes, people! Quotes! Can someone please find some others that might add to this conversation?
Of course, if you don't want to look up quotes, I'd love for you to share some of your own...just let me know they're yours, k?