I definitely feel this way sometimes. I'm 40 and just figured I was aro/ace a few months ago.

But it's being bi that brings on impostor feelings for me. Nearly all my life I kinda just assumed I was a vanilla straight dude. But after the ace/aro discovery I kept exploring a bit and deconstructing what sex and gender really are. As I did so, it was like all these restrictions I didn't even know I was under started to lift.

It's strange because wasn't like I'd been repressing anything all these years. It was more akin to finding a door in your house that you'd never noticed before, opening it up, looking inside, and thinking "oh shit, I like everything in here! has this room been here the whole time?!"

So, sometimes I worry people will hear that and think I'm just having a mid-life crisis or appropriating lgbt culture for attention. I mean, the ace/aro part came as no surprise at all to anyone who knows me, but bisexuality was like an unexpected bonus.