On a different vein, a sort of side note, if you will, I've taken up yoga because of sensory issues. My body is 90% numb to me. So, for me to spark feeling, it is an immense pleasure. I don't feel pain usually, unless it's really intense. When I do yoga, I can feel the muscles come to life.
As for intense focus?
Pretty much the same as the person who mentioned gymnastics. Except my parents neglect meant that I never had extracurricular, so I never got the chance. When I was stret hing/yogaing in the hospital, a person had a friend who had been in ballet for years, he had unpromptedly commented that I dance, and very well. So, ya. I studied it intensly, but more the logic behind it, as I need rules and steps to do anything, until I was able to understand the how, why, and what of dancing.