Maybe we haven't been aware of adults' ability to learn so well because our society demands a narrow system whereby (and this is a simplification to make a poin

Maybe we haven't been aware of adults' ability to learn so well because our society demands a narrow system whereby (and this is a simplification to make a point) kids only have one shot to master one specialisation when they grow up, and then they have to stick at it for the rest of their life or else risk economic vulnerability. I know you can have a second career (and master it over many subsequent years), but the structure of society does make it hard for a full-time working parent of five to suddenly stop earning income for a while go back to school (or study with a master). So the data on this could be low due to that.