No, you’re missing the point. I went to school in the 80s and learned this stuff without multiple choice and fully understood it all of the way through undergrad where I took up through calc 3 and differential equations. Then I spent nearly 30 years as a SWE not using it and forgot nearly all of the details within maybe 15 years.

This happens with very basic things like human languages. Bilingual people can forget an entire secondary language if they don’t use it for a decade+.