This is such a feel-good tale for atheists. Growing up as one of three Jewish kids in a predominantly Catholic town, I've always known my parent's beliefs are not everyone else's parents beliefs. I think that's made it much, much easier to discard them. When you're placed outside the norm to begin with, it doesn't hurt to switch to a different outside-the-norm belief. But, it wasn't like that for you, and for that I applaud you even more.