Fetishes

I'm genuinely curious as to how fetishes develop because I know they can develop due to a certain life event or experience but what about those that are just random fetishes that's just been there from day 1 for no reason T.T

Personally I know that I have a fetish for being spanked and that has lead to more fetishes because of that one fetish but I have no clue where the spanking fetish came from. I hate pain and haven't been spanked in my childhood but I clearly remember me being in 3rd grade and searching up "boy being spanked" and other things along similar lines in tech class and whenever I saw it I just knew that it was something I've always liked before reaching adulthood and realizing it has become a turn on for me atp.

And going back to how I hate pain, for some reason spanking is one of the only things I'm okay with that's painful like being hit anywhere else? Nope I'm good. But I'm genuinely curious how that became my fetish because there's literally nothing that has triggered it but Ive always just had this strange obsession with it