Wow Fi, that's impressive to me. I was just so dense I didn't know I was trans until last year at 72. Wish I had known it sooner. Shoot, WISH I HAD BORN FEMALE.
I know of many TS who began their transition in their 50's and 60's. I know two not on this site older than even me. (But actually I am only 42! just happened to have been born in 1935.)
I know a most precious girl that I am recommending this site too. Her parents kicked her out into the street the day she became 18. but she has on her own gotten her gender counseling, name change, hormone treatments, since she was 16 and is having the SRS in 4 months. Many of us TS's wish we were in her shoes or had been at that age. She is just 18 still.