I'm thinking you're misunderstanding the definition of "choice". You seem to think it requires the sentence "I think I'll believe this". In fact, that is exactly what you did, albeit without those words: you made a choice between "This seems real and true to me, and that does not."
No, I didn't. I just found a name to apply to it.
I see. So your contention is that you emerged from the womb believing there were no gods and in some form of anatman (you didn't specify WHICH type of Buddhism it was that you were "genetically programmed" as), lived all the way to adulthood in a Christian family somehow thinking that your beliefs were Christianity, and then discovered that what you were REALLY "born as" was a Buddhist of some sort?
I'm dubious.
Sounds a lot more to me like you made a lot of incremental choices about what to believe throughout your life, didn't recognize them for what they were, and then rewrote your memory to suit what you wanted to believe . . . also a choice.
I will also offer you the evidence of people who were NOT raised in any sort of religious belief who, in fact, do exactly what you describe: sit down and decide they are going to believe in a religion.