As Admin notes, "always knew" has many interpretations. I always knew I wanted to be a boy, I thought I should have been a boy, I thought I felt like a boy, I had a male identification...but I did not know about trans people until I was older, and I didn't know about FTM trans people until well after that. Am I less trans because I didn't say, "OMG, I'm trans" until I was twenty-six? Or because I didn't say, "I AM a man" until I was nearly forty-six? I'm the only one with authority to answer these questions.
The old rules have changed. We don't need to spout the party line to get hormones and surgery. A lot of people don't absolutely fit the old narrative. There's no reason to lie anymore.