There is an old Talmudic adage that goes something like this:
He who learns in order to teach will be able to learn and teach, but he who learns in order to do will be able to learn, to teach, to preserve, and to do.
(Avot 4:6, in case you're wondering)
I've always applied this to my learning of anything, and especially Judo. The idea here is that the study of Judo isn't just academic, but part of our lives in more ways than one. I once commented on the JudoForum, that Judo creeps into my life in the strangest of ways - for example, I sometimes find myself using foot-sweeps to open doors when I don't have a free hand.
As I get more senior, and as I help out in the kids class, I am seeing this more and more with my own eyes. The techniques that I had the hardest time with as a beginner, and the ones that I spent the most time learning and working on, are the techniques that I enjoy teaching the most. All of the advice that I never took until I learned the hard way has become all of the advice that I dole out.
And of course, the ones that I've been asked to demonstrate that I didn't really know, are the ones that I feel challenged by even more when I am practicing.