I realize this photograph is likely from a Japanese movie,
but I like it for it shows in my mind where I believe Okinawan karate came from. No special uniform, No belts. Just someone in their street clothes doing their art.
It also makes another point, all of the really highly skilled individuals I have trained with, came up from the bottom, where they were continually on the receiving end by their instructor.
They could do it because they had it done to them over and over. Then when instructing a student, they know from remembered feel when the hold used is in the correct place, or where it needs to be adjusted.
Just being able to show a technique is not the same as really knowing the technique.
The last photo makes that point.
Even Bruce Lee was able to take the fall to instruct.