Most of the ones I know didn't break away from anything - they were raised without religion and haven't much thought about it. The majority of our population is secular, with a lot of tolerantceof those who are religious. People are pretty free to do what they want. But generally people stay with what they were raised with as a choice or in a passive way, be it a kind of positive atheism or secular humanism, or a religious belief, or most just not thinking much about it at all.
Different parts of the world I guess. I grew up the deep South... the literal Bible belt. To meet anyone non-xtian was extremely rare when and where I grew up.
I grew to be an adult and moved to the big city and made friends like the ones I described.. ones that had left religion after much thought and sometimes, heartbreak for their families of origin.
Gotta concur with Philomom. In the US, it is difficult to find someone who didn't grow up under the burden (my description) of a faith-based family. Even now that I'm far away from my family in a town where I blend in with the crowd, I get approached by individuals who ask me "Are you "X"" in order to say a prayer or whatever with me. I can't escape it. American politics are dominated by faith-based initiatives and what-not. It is ever present.
Regarding the most recent posts concerning absolute "truth" (I'm a Zoe's mom too, by the way!): There are some who would say that the absolute truth is that if I don't accept you-know-who as my personal savior, I'm going to hell. My absolute truth is not that there is no hell, or that you're not right. My absolute truth is that I don't care what the position is. My absolute truth is that morality is not part and parcel of any one religion. I can hold and subsequently teach my DD moral principles without the need to connect such principles with a god.