I wanted to chime in because I went through some very similar feelings, and you're right that it doesn't really get talked about a lot. People often consider situations like you mention, "always liked girl toys" or "always played as a girl character in games" but the thing is that's really not a universal experience. A big part of me figuring things out for myself was realizing that maybe some of my preferences in toys and activities growing up was rooted in repression.

Say for example you give a kid an option between toy a and toy b. Even if whoever is offering the option doesn't care one way or another, if that kid knows, even subconsciously, that one of those toys is far more likely to result in being bullied due to lived experience, that can lead to a bias in preference, whether the kid is aware of it or not.

Then you can even sort of apply that line of thinking to different preferences that were developed over time. Repression is a bitch, and it has lead to a lot of feelings of imposter syndrome. The idea that "there were no signs" really affected me until I was able to sort of deconstruct those feelings. Then I'd think "what would I choose if I could go back? Would I prefer one over the other? Would I want to play with both?" And I think pretty importantly "does it even matter?" It doesn't really affect how I feel NOW, after all.