@taedryn hm, I used to wish I was a girl for a really long time, although not as intensely as some of the other people who replied to you did? The first occurrence of it I remember was at like, idk, 6-7-8 years old? And then just kinda occasionally thinking about it throughout adolescence?
But even after I learned about trans people existing I didn't figure it out until I was 18 lol, despite literally occasionally being like "huh that's interesting, I kinda wish I was like that too but maybe it's disrespectful and weird to wish for something like that so I won't think about it any further" as a teenager 💀
The fact that my only interactions with trans people were through anti-SJW subreddits I used to frequent as a shitheaded teenager definitely didn't help 😬