From a physiology lecture the other day:
“People have trouble understanding the development of the osmotic gradient in the kidney’s medulla and so they give up on renal physiology. But the truth is nobody needs to know how it’s developed, just how it stops you from dehydrating.
Lecturers who teach it don’t understand it properly so they can’t teach it properly. So the students aren’t really expected to know it because it’s never presented in exams.
If you happen to go into this field and then get a job and your boss asks you if you understand it, say yes. Because the truth is he doesn’t understand it so he won’t be able to quiz you on it and no one uses the process, just the effects that result. It’s really just an academic exercise for geeks.”