Often felt a genuine teacher was a Miner-Jeweler. A poor one creates mass produced costume jewelry, a tragic quality of student, pretty, shiny but of little/no genuine value unto itself.
Whereas, a bone-fide teacher craftes, hones the stones which cross their path. The process (IMHO-fwiw) requires years of time to carefully study the base material and hone it to a gem of rare and unique value.
I like being a "miner" myself (seeking a .gif with a miner's hat with the light on top of it) equally difficult but very satisfying. Back to the ~kata mines~ for me