A childhood belief about rude bits

When I was a youngster, I learned about circumcision in such a way that I believed it was reserved for Jewish people. Later, at a friends house, I saw an image in a foreign porno mag of a man who was missing the head of his penis (I don't know why, I couldn't read the text).

This lead me to believe that Jewish men were all missing the head of their penes, and that's what circumcision was.

Here's the worst part:

This stayed with me until I was 23! It was very embarassing when I mentioned to a girlfriend that I couldn't imagine having a circumsized penis, and she had to tell me that I was very silly because I was circumsized. I was lucky that she thought it was so rediculous, that I must have been joking.

I had to look it up later to find out why it was funny.