Sometimes they'll need formulas they don't understand (can't motivate) for doing work things?

Then what? Are they going to incorrectly use anther one, a wrong one, because they understand it better?

(Searching not where one lost the key, but where the light is stronger)

Hmm, I wonder if you studied stats? It sounds as if you studied lots of math.

I did long ago, mostly forgotten, and, hmm, I don't think there's a single real life useful probability function one can understand, without knowing the underlying calculus? Except for understanding in the sense of trusting the teacher.

Which works pretty ok in medicine