Does eating cheese before bed give you nightmares?
I suppose it has come from somewhere in the past because, say tea, at one point in time was toxic, and people used to have all kinds of problems with that. I've not read the historical source of where cheese was regarded as being bad. I sometimes wonder, whether in the 1950's when people were alerted to the effects of cheese on a particular type of antidepressant which is associated with a high increase in blood pressure. Whether that particular public health campaign didn't impact the general view that cheese might impact on dreaming and nightmares.