See, I always thought the original was more along the lines of “those who can no longer do…” as in the elders who maybe can’t do all the physical stuff, teach those who can.
Teachers deserve respect because they maybe can’t jump up and kick an opponent in the head anymore, but they’re wise enough to know they don’t have to. That’s the student’s job. Teachers are wise enough not to get hurt.
There’s a similar ridiculous phrase… “it’s better to ask forgiveness than ask permission.” Someone recently used that in a meeting to discuss making alterations that would affect an historical property, including tearing up part of a 200 year old cobblestone street (this is in the US, for you europeans… 200 years is really old here), and I couldn’t help blurting out “that’s a motto only assholes live by.”
Keehan actually had some good ideas. F’rinstance he would have his students fight in a (simulated) bar in their street clothes. That was radical in the day.
The most impressive breaking demo I ever saw was by a Silat and Kuntao Guru many years ago. He told me to go out and get a rock. I got a nice big piece of basalt from an empty lot next to where the seminar was. He put it in one hand and did this loose, whippy palm/palm heel strike he has and broke the rock. I know it wasn’t treated, and I’m pretty sure he didn’t have anything else in either hand.
A slight warning: The instructable link in the post says the direction of the grain in a board you want to break doens’t matter. Which is very much untrue for non-square boards. Breaking boards with the long edge parallel to the grain is much harder then with the short edge parallel.
I knew an instructor who would sometimes invite his better students to a local bar where the army kids hung out. Things would happen and they had some fun. It wasn’t until several years later that I learned one of the base master sergeants was in the habit of inviting his troublemakers out to that same bar to learn they weren’t as tough as they thought they were.