I know I was raised in the church for the most part with my mother. Her father was a baptist preacher later in his life. So I can def say for the most part it would be from being taught at a young age. Those that convert later on in life often seem to have been in a rough patch when someone approached them with a good 'Jesus saves' sales pitch. I'm not saying this is always the case and I'm certain even if it is the case for most people they will probably deny it happened that way.
I'm no one special and I treat everyone the best I possibly can, but to you believer, despite my acts, I am condemned to hell.