Now, this brings up an interesting thought. More “memorizable” something is in this sense, also makes the knowledge feel “brittle”. And that type of knowledge also feels less “important”, in that perhaps it’s required for fluency (easily and smoothly communicating in a language or a given subject), but losing that knowledge is not a blow to some deeper level understanding of a subject area. Blanking on a definition or abbreviation is really only a time cost, not a knowledge cost.