I'm a Catholic because my parents were Catholic.
They were Catholic because their parents were Catholic.
If my parents had been Scientologists I'd probably have a poster of Tom Cruise on my wall.
It's weird when you think of religion this way. It's not like you have a choice. It's not like, on that day that reason kicks in (whenever that is), you are sat down in front of a Power Point presentation and asked to choose which religion you like best.
As a baby I was baptized, and that was that. They dumped water on my head, and it was official. I later learned that if, on the way to have water dumped on my head, I got struck by lightning and died, I would not have gone to heaven, but rather a place called "limbo", defined as "the border place between heaven and hell where those souls who died without being baptized, though not condemned to punishment, were deprived of eternal happiness with God in heaven."
So us Catholics have that going for us, which is nice.