I also didn't stutter as a young kid, I think i started when i was around 10 (im 30 now). So as far as i know, i didnt stutter for the first 10 years of my life which to me is a bit odd since it seems like its way more common to stutter as a kid and the you grow out of it when you get older, or that most people who stutter has always stuttered since they learned to talk. You're lucky to have gotten to the point where people mostly cant tell that you stutter, that is not the case for me, although i would say that my stuttering is mild to moderate. I have accepted my stutter but it still bothers me, and it has most likely changed my personality and made me miss out on many things in life, but i only have myself to blame for choosing to avoid many activities and social interactions. Well anyway, it was just interesting to see that im not the only one who started to stutter later in life.