I do think a lot of common cultural how-to knowledge was destroyed around the middle of the 20th century by the new corporate "mad men" advertising world. For example, complex knowledge of cooking was universal, passed from generation to generation from an early age, then along came heavily advertised processed foods and within a generation, vast swaths of the population have much less know-how being received from their parents, just favorite brands and how to boil the mac and cheese. So much cultural traditional knowledge was lost when it was replaced with mass manufactured "junk culture" and only later are their descendants slowly reaccumulating it.