tapanda:
Athiest here. Can't really say I have as good of a reason as everyone else that's posted here. Grew up in a non-religious environment and was allowed to explore whatever I wanted. Didn't really enjoy anything that I found, and definitely didn't believe any of it. (At the age of four, I called the children's book of Bible stories "Bad fairytales" to my uncle, who is a pastor.)
ApronDoubleBelly:
I believed in the fairytales far top long. I hear of many raised in religious homes who wised up much younger than I. I wasn't such a free thinker but a blind pleaser until. Age 36. When I look back I'm appalled by my blindness
People fall in and out of religions at all ages, and really I'm not too surprised that 20s and 30s tend to be when people realize religion isn't for them. I guess I just don't usually see the harm in most religious doctrines, as long as specific parts aren't used to attack or vilify other groups of people.