It reminds me a bit of an anthropology question I've heard brought up a lot that's sort of the dark inverse of xkcd 1053 [0], that many things that "everybody knows" tend to get lost over enough time. You don't need to properly cite experiments or lectures or books that "everybody knows". Especially when the work you do essentially replaces those things in the canon, such connections sometimes get entirely lost. To an anthropologist working in some ancient language the variations of the phrase "as everybody knows" are often a missing or lost citation today. The places where it is so implied that you have the same education or background or textbook as the author to not even warrant an "as everybody knows" is an ever worse thing because you don't even have the marker that you are missing a citation.

[0] https://xkcd.com/1053/