It must have something to do with all the schools catering to kids. The perception becomes that that is the norm, and by the time you reach 20 it is time to retire. Martial arts are for kids, and adults who continue to train are weird/nerds/abnormal/ā¦
Funny thing for me, when I began training I was age 13 in a class of adults. I felt like the oddball for being so young, I perceived it as an adult thing to do. That was 1984. Times have changed.
This is what I'm experiencing. Even the "adult" class age starts at 13.