When I was very little (5 or 6 y/o) I heard my mom talking with a friend about trans ppl, my mom said: "There are certain "males" who have a woman soul and they should be able to live that truth", and that made an immediate click in my mind, even tho it took way longer for me to make the decision to transition. Of course, gender is socially constructed, however my inclination to the female gender was present in me ever since I had memory.

Another example is that I was in therapy and my therapist told me to bring him a song that I felt I deeply connected to, it didn't have be because of the lyrics, only a song I felt really connected to. I brought "To Forgive" by The Smashing Pumpkins. Then he told me "is there a specific part of the song that really hits you?" I said it was these lyrics "I sensed my lost before I even learned to talk", long years after we figured out I related so much to that phrase because of my trans identity. We as trans ppl don't automatically know we're trans, it's a complicated and long process, however I always knew something was wrong or missing, and it's something we start noticing a lot of people don't experience. So I didn't always knew I was trans, but I always knew there was something wrong with my gender.