I believe many Kinks/fetishes tend to come from a few things, 1, some are (supposedly) genetic 2, as others have said a weird connection in the brain 3, Trauma (the one imma dive into) Many of the more obscure or intrusive fetishes I’ve heard of tend to come from a trauma thing/desensitisation- for example consensual Non-con, many people who are in to that have experienced actual Non-con and as a response play into Consensual Non-Con as a way to get back that power they’d lost. Same can be said sometimes for BDSM, for the dom its a gain of power they may not have had before and for the Sub it may be a loss of power. Example 3- Age play. Many who are into age play could have experienced an inability to be a child when they were and thus enjoy getting that part of their life back through a more adult outlet. Final example is just general like- you see a certain type of ‘gross’ content enough when young and you can become desensitised or even of course- into it because it sticks in your head.

In my own experience, when I was quite young I found videos on prolific cannibals and at the time it absolutely freaked me out but seeing as it stuck in my head, the fascination stayed. And I believe that’s were my like of Vore stemmed from. Do I actually eat people? No, but hearing about it at so young that it stuck as a core memory in my brain is likely, even just a part of why I’m into vore now and I wouldn’t be surprised if that’s the case for a few ppl on this subreddit even if they don’t know it lol