Well the med school textbooks are based on research. There are sleep institutes, studies, labs, specialists and an industry with a whole big line of products ... I found references saying things like "we all know that water can ..." "It's common knowledge that ..." but why no research?

Why wouldn't your doctor say "Hmmm, interesting. I haven't seen or read or heard this before but hmmm. You may be right".

Where's the curiosity? Is it because "water" or even the act of "not taking something or other" can't fund a research project?