Haha, don't worry. A lot of people don't know that.

But basically, Mohammed took a bunch of the stories from the Torah and the Christians, and put them in to make it seemed authentic. At one point he actually liked the Jews (in one passage, it refers to us as "our brothers"; they hid him from his enemies at one point), but when they wouldn't convert over, he had the town wiped out. And then he said "Okay, don't like them anymore. Kill them...in the3 name of Allah!" So yeah...

Amazing what you can learn in a foreign country...