We don’t choose the things that turn us on.
While I agree this is true to some extent, I don't think it hangs there entirely outside of our control. One may have an interest in vanilla sex but have a real sharp fantasy for NC sex. I believe if a person focuses his or her sexual satisfaction (and basically I mean by masturbation) on the fantasy of NC sex, that person will "shape" themselves to be more and more reliant on the NC sex theme and less and less responsive to vanilla sex in real life.
I used to feel guilty all the time for having the fantasies but learned that they were more common than I had thought they were.
Rape fantasies -- all kinds of bizarre fantasies -- are more common than some poor lone fetishist feels. The internet has been fantastic for providing a community in which one may feel accepted. That has, as I have learned, real worth in one's life. Further, though I was far too young to pursue this path, the internet provides the possibility of overcoming that hurdle of sexual suitability with a real life partner prior to getting to the tougher business of life-matching suitability. But community also risks what I mentioned above, the focus on the kink above the real life suitability, including vanilla sexuality, with a partner. Focusing on the kink can leave one unable any longer to get excited by vanilla sex.
And I say this as a man who has not had an "eyes-closed" fantasy in which the woman has consented for 25 years at least. And even prior to that, a consensual female appeared in maybe a dozen fantasy sessions.
Ruined my life, no. Changed it in ways that were not always desirable, well, yes.