I am 41. I started training at age 13 in Kyokushinkai (a lot of which I liked very much). I stayed with that until age 17 when I began studying JKD. Later on would come boxing, wrestling and everything else.
I haven't trained consistently of course over the length of time (13 to 41). Occassionally things would get in the way. Things like education, marriage, children, jobs, etc. But I always managed to get some training in.
At last count, I've been training very consistently for the past 11 years (Brazilian jiu-jitsu/submision wrestling, boxing, savate, muay Thai and some things that some folks might call combatives. Personally I think it's ALL combatives.)
Now I've suffered a shoulder separation that will put an indefinite hold on any further training. It sucks not being able to get on the mats folks. Always train safe and smart.