Jill, a black belt who was teaching me at the time, made it her mission that I was GOING to learn this self-defense on her watch. No exaggeration, she probably made me do it 50 times in a row in class one day. I thought that she was being a persnickety nitpicking pain in the ass, but this generally not being the kind of thing one *says* to one's martial arts instructors, I sucked it up and did the damned thing the full 50-odd times until I had it down to her satisfaction.
Anyhow, fast forward to tonight. A different instructor asked me to work with a yellow belt on his self-defenses during the open mat time after class, and darned if he didn't ask about that specific one. Every time I opened my mouth to say something to him about it, I could hear Jill's instructions coming out, even after four years. Uncanny. Repetition is an amazing thing.
In the martial arts, it's tough to 'pay back' your instructors. They give you the benefit of their training and experience, but in return essentially you can only serve as a body for them to practice on. The tradition is that you thank and honor your instructors by learning well and then passing what they have taught you down to students who are junior to you. Today's instructor thanked me after class for working with the other student, and I told her sincerely that it was my pleasure. I had an old debt to pay off.