heh me too. If i had started 2 or even 3 years ago i would have been in bogu long ago. Instead im almost in bogu. Oh well Shikata ga nai. Still as we see in the thread 16 is pretty early. Though when i have kids they are going to be doing it the moment they can possibly hold a shinai.
the most "dangerous" guys doing kendo in japan is in the range 40-50 i think. Some get their 6dan around 35-40ish and in the years 40 to 50 they still have a lot of speed and power left. That combined with about 30-40years of kendo...