I wanted to start it since I was a kid in the 70's watching Bruce Lee. Unfortunately, back then (given the ignorance of martial arts) you were automatically labeled a "Black Belt" and were required to fight everyone on the planet to see how tough you were. (There was only nothing or Bruce Lee...no in between and I was the smallest kid in the state).
I started it many years later as something to do with my middle son.
I signed up for it because they have lots of mirrors in the dojang and I saw the reflection of an overweight, out-of-shape, fat, ex-athlete in them. Unacceptable! Humiliating! My self inflicted punishment was to continue even though I HATED IT!
I continued it because that only lasted 2 weeks. Loved it ever since.