I think this is a bad question, because it has some unhealthy assumptions about human development. I think the way people develop is incredibly complex, and I doubt there’s a neat explanation for any topic regarding human sexuality, or human behavior in general, even if we like to think there should be a simple “origin” to something like kink.
I mean, there’s a bit of a chicken and egg problem, right? Do we pursue the kink because we are initially interested in it, or does the interest begin to bloom through experience and exposure to the kink itself? Let me put it another way–is it possible to really imagine someone who is “into” bondage prior to any knowledge or experience of bondage? Don’t we need the word/category before we can begin desiring it?
My larger question is this: are we somehow developmentally hardwired, either by nature or nurture, to desire certain things, sexual or no? I mean, there is, of course, some fundamental sexual desire which is fundamentally natural, but the point at which is blurs with development and choice becomes very, very murky.
Honestly? I don’t think kinks are part of who we are at all. I enjoy piss, and rimming, and pits, and all of these other things, but I don’t enjoy them because they originated in me somehow–I enjoy them because my experiences with the acts have all, by and large, been pleasurable. I do my best to take full responsibility for the things I enjoy–I don’t feel alienated from them, like they are some force within me that I can’t control.
Your kinks are yours. Own them. You made them. It isn’t something you should feel ashamed of, and alienating yourself from your own desires will just make you feel awful for pursuing them.