I'm not sure if this counts since it was college, aka training for the professional world, not the professional world itself, but taking some psych and teaching classes made me realize just how far those two professions are from hard science and how susceptible they are to stupid academic fads that turn out to be completely ass backwards ten years down the line.

Basically, teachers and psychiatrists' methods are based on theories pulled out of some big brained person's ass at some point with the hope that it will work, and depending on how much the intelligentsia who are the trend setters in that field love that theory because it aligns with their view of the world, that's how stubbornly they'll cling to it, regardless of what statistical evidence says about if it works or not. With education it's much worse though, because despite them clearly showing that educational theories and methods are constantly changing, the education system still demands that all teachers conform to whatever incredibly narrow techniques, methods, and criteria are popular at the moment. At least with psychiatry if you go into it you'll get a little freedom to experiment on your own within your personal practice. In education that almost never happens.

Right now in education, coddling is all the rage, structure is supposed to be incredibly loose, and you're never supposed to punish students for doing badly or reward them for doing well, FYI.