My wife was/is a children's librarian, so we always had two sets of encyclopedias in the house. We eventually got her down to one, and only recently, none. School libraries would rotate them out when replacing them, so we would tend to have a set that was five years old and another that was ten years old, or some such. When my 39 y/o son was about 9 he had to do a report about nutrition and started with the encyclopedia.* He chuckled at the line "Butter is highly nutritious," as even he knew in 1988 that wasn't right, because of what he had absorbed from his mother's dietary dictates. It became a family joke for years.
Except, as you know, things gradually changed and margarine was exposed as more of a problem than butter, and now, decades later, butter is considered superior again. That son now thinks he might like to have a complete 1911 Britannica, but otherwise, no encyclopedias.
* Tracy insists that starting with the encyclopedia is fine, it just cannot be your main source. She would know.