Title says it all.
What do you study, how long and why stick with that art?
Myself, been in karate since I was 11 (25 now) and did three years of Brazilian jiu-jitsu a few years back.
Just started a new style of karate (goju-ryu) and had to start at white again. Thank God I don't feel pride or mine would have been hurting.
I love martial arts more than motorcycling and that's saying a lot. If I hadn't taken up the art, I wouldn't be in the career I do now, nor would a lot of other positive things happened to me.
I also don't just do it for fitness or to learn how to take care of myself. For me, it's a deep spiritual commitment and one that I take very seriously. I'm sure there are others who don't feel the same way and wouldn't mind hearing why you took it up in the first place.