I grew up as a Lutheran Christian in a small, conservative town—and attended Sunday School/summer Bible camp for many years—but became an agnostic after I began questioning things at 16 years old. About a month after that, I became an atheist. I’ve been one since… so almost 14 years.
Unfortunately, I was afraid to tell my parents, so I still went to church with my family almost every Sunday until I left at 18. I was also still effectively forced to be anacolyte/perform piano/sing in the choir/attend most other church activities. Fucking painful.
I still haven’t told my parents, though, and probably never will; it’d cause more pain than anything else, sadly.