A lot of atheists tend to know more about religion than most religious people. I've read parts of the bible as well as the book of Mormon.

I disagree that religious people are humble in their beliefs. They have missionaries who will go around to people's homes and thrust the illusion of Jesus and heaven in their faces. Just today I had two Mormon missionaries at my door and I proceeded to hide because I didn't wish to be told how terrible of a person I am.

I would consider myself a humble atheist although people tend to stir me up about my ideas. I've gotten into more religious discussions because a fundie was shoving god down my throat than when I have instigated the conversation.

The atheists you seem to know are more anti-theists. This means they completely loathe the idea of religion and everything it stands for. I am an anti-theist but I don't precede to push my beliefs on anyone.