This American Life has a great article ALL ABOUT MONEY.
What is money?
Why do we think it's real? Etc, etc, etc.
Listen to this episode here: WHAT IS MONEY?
I scooped this story though. Back during the heart of the financial crisis, I too asked "How did 1 trillion dollars just vanish?"
And I discovered, that none of it was actually real. It was all debt that people were trading as though it were money. Not that money is real either. But there were no paper bills. there were just numbers. That's it.
The financial crisis is just a big stupid hallucination.
In the August of 2009 I made this video (forgive the rapping at the beginning):
But really, you should really listen to this article