I went to Baptist church and Baptist school until fifth grade. One day during religious class, after the teacher said that people who don’t take the lord as their savior go to hell, I asked what happens to all the people who never have the chance to hear about God. “Everyone has heard about God,” she said. That just can’t be true, I pointed out— there are still remote tribes being discovered in the Amazon, for example, and that was even more true 200, 300, and 500 years ago. There have been literally billions of people who never had the chance to hear the Bible version of God, did they all go to hell? She just stubbornly maintained that EVERYONE has had the chance. It was so completely and obviously wrong that whatever child-like faith I’d had broke and drained away in an instant.
It was like when I realized that Santa had the same hand-writing as my mom: I saw that the story was made up, but absent the story the main event was still exactly the same. I still got presents and cookies and decorations and everything I loved. The made-up story didn’t enhance it particularly, and realizing it was false didn’t detract particularly. In the same way, once I realized the Bible stories I’d been studying daily were fake, I didn’t feel some big loss in my life. So I suppose you could say that I’m an atheist because I have a more-than-fifth-grade grasp of logic and because my enjoyment of life didn’t require clinging to falsity.
And of course because all the kewl kids like PZ Myers are atheists, too!