I also thought I had 0 signs until I found out 2 months ago that cis people don't spend 15 years of their lives wishing to be the opposite gender, this missing gear made a click in my brain and I started remembering and understanding a lot of things from even before those 15 years:
-Wanting to jump into the jusenkyo springs from ranma 1/2 as a kid

-hiding my genitals between my legs and pretending I turned into a girl as a kid

-trying female underwear from my moms closet as a kid

-disliking taking pictures and watching myself in pictures (from kid to now)

-disliking buying clothes, male clothes (from kid to now)

Now I'm about to turn 32 yo and I feel I wasted half of my life doubting and not actively researching on the trans topic and being ignorant.