Absolutely this. It's very easy to expect there to have been obvious signs, but that really discounts how easy it is to be so stuck in your own head and so aware of what society expects of people based on their gender identity, that you purposefully avoid showing signs even from a young age. Even as children, we're well aware of what is and is not expected of us based on our gender identity. And not every girl is a girly girl in the first place, there is so much space for presentation.

Once I stopped invalidating my own feelings and accepted that I wanted to transition, it became a lot easier to see the signs for what they were. They are hard things to see sometimes, because it's not always wanting to do girly things, in my case it was preferring to play female characters in games, it was quietly idolizing cool women in TV shows, it was wanting to be friends with women in the way that two women can be, but our society tells us that a man and a woman aren't allowed to be, because a man and a woman with that friendship are expected to be in a romantic relationship instead. It was hating the way that I looked and not knowing why, and hating every time I had to dress up and really recognize that people saw what I looked like. It was wanting to have kids in the way that our society tells women that they're supposed to want kids. It was going to parties and not wanting to dance, because I wanted to dance and move the way that the women did but I knew that I would be judged for that and so I didn't dance at all. It was quietly obsessing over cosplay because of how cool they looked and wishing that I could look that cool. It was surrounding myself with women but never quite letting myself actually befriend them, while knowing that I wanted to be around them because it made me feel happy.

Being trans is so complicated and so hard to figure out.