What really had me beginning to question things more was the whole genital preferences discourse, and what brought it to my attention was a conversation I'd had with a gay male friend in which he'd told me that his ex from his teen years was actually a FtM, now FtMt??? (in retrospect, I could have easily inferred that from what he'd told me of her). I found it so jarring when he could say something like "wow they don't lie when they say that trans men get really wet!" and still call himself a gay man.
I've found out even more recently that he doesn't even enjoy banging pooners - he just does it because that's the best he can get. I think he never admitted to it until now because of the assertion in left wing spaces that trans people are who they say they are and should be treated as such no matter the context, but I suppose I've proven myself a suitable confidante.
Of course, this is merely the event that got the ball rolling. That alone wasn't enough to make me reject the entire ideology. It then occurred to me that non-binary (a concept I'd previously thoughtlessly accepted) was really just an escape pod from traditional gender roles that also reinforces them. Then I began to realise the sheer number of troons and poons who openly don't experience dysphoria, and of course, that they're no different from the non-binary crowd. When I was a teen, I witnessed the cotton ceiling debate, but I was too immature to really get it. I did however at the time, learn about non-dysphoric trans people, and was rather disturbed at how many of them were self-proclaimed lesbians. Because of social pressures, I just pushed down that discomfort. Just because I don't understand something doesn't mean I can't accept it, right?
Also rather a subjective claim, but almost every person of gender I've known directly or otherwise IRL has been a massive creep. Pretty much every pooner I know has dated a minor. I know troons are often seen as the predators, and I agree, but I would not leave a 12 year old boy unsupervised around a 19 year old Aiden.