For me, there really isn't any one thing.
I love the feeling I have after a good class, when my legs are rubbery, I'm drenched with sweat, my blood's pumping, and I can barely walk to the car. I feel so ALIVE!
I love making friends within the dojang, and being able to hang out on and off the mat. Some of them end up being some of the greatest friendships.
I love sharing my knowledge with others, and watching others benifit from what I can offer.
I love receiving knowledge from others and my instructor, and the fact that I learn something new every class, and will continue to learn something new every class, no matter what rank I achieve.
I love being humbled in a sparring match, especially when it hurts.
I love having to push myself to go just a little longer, just when I think that I can't give anymore.
I love the pride that I feel from my family; from my mother, father, sister, and wife.
I love the fact that I will have SOMETHING that I can actually teach my children and know what I'm talking about.
I love the fact that I have accomplished at least one of my life's goals, and that the goal will actually never be truly reached, since being a blackbelt starts a whole seperate journey.
I love the security I feel walking into a clearly hostile environment, and knowing that I can take care of myself.
And, finally, I love proving to myself everyday that I am good at something, and that I can always improve on what I do.