[antiutopian]

So if your explanation is right, then we should also expect to see only a tiny effect in the practical use of math, reading, writing, etc. between people who went to school and people who didn't. Because only 2 cared enough to pay attention. Right?

[pjscott]

Beyond the really elementary things that get repeated often enough and insistently enough for most people to learn them whether they're interested or not -- basic reading, basic writing, addition and subtraction -- yes, as far as I can tell most people don't retain much from school. Not for long, anyway. It's easy to think otherwise if you're (for example) an engineer surrounded by unusually studious people in your day-to-day life, but standardized tests administered more broadly give a less encouraging picture.

[abecedarius]

https://en.wikipedia.org/wiki/The_Case_Against_Education looks at research on retention and finds it to support you on this point.

[wonnage]

Sometimes it's not a retention problem, it's that they never learned the stuff in the first place. You're pretty doomed if you fall behind in school, it's all up to some individual going above and beyond (a teacher, a family member, a friend) to save you, because the system will just keep shuffling you along to adulthood, and then all the consequences hit at once. Take this loan with compound interest you can't understand because you can't multiply, buy a massive depreciating asset with it (car, mobile home...) because you don't know what "depreciating" is...