In your OP you said that you’ve known since you were 17 and perhaps had some hints about yourself as far back as puberty, which seems perfectly reasonable.
I was wondering what your opinion is on those rare cases you hear of much younger, prepubescent children who identify as the opposite sex (which I think is okay in and of itself), who have parents who provide them with treatments such as hormone therapy and puberty blockers, which I think could be potentially quite harmful to a child’s development. Especially if it turns out that the child changes his mind and is not trans after all.
I mean, I remember liking girls at the age of six, but a lot can change between the ages of 6 and 12.
No one in the trans community is advocating for any sort of medical transition for prepubescent children. The Standards of Care for that age is all about treating them as they gender they identify as, and waiting to see what happens at puberty.
If the child decides to stop taking them, then the effects of blockers pretty quickly fade and puberty resumes as normal. It doesn’t actually cause transition, so much as give a teen more time to decide for sure. You aren’t allowed to start HRT proper until 16 usually, and the potential risks of harm stem more from having to be on blockers for that long, rather than doing that at all.