Well, I think there's a fairly large difference between a person my age struggling (perhaps unnecessarily) with short-term memory loss and children who cannot remember their lessons or to do what they've been tasked with. I don't have too much trouble remembering the more important things; I'm still quite able to learn new things and - for the most part - think clearly and focus on what I'm doing.
As for kids, my youngest (who is grown now) simply was not interested in anything that didn't fully entertain him. Talk about not living up to his full potential. Yikes he was such a handful. Now he's in a management position where he works, and he's doing just fine, both in his work and as a family man. Part of the issue with him when his teachers (and I) were fussing about his 'potential' was that he could not relate to the teaching methods in public school. Work with him one-on-one, and he was plenty smart. He just needed to have his full attention engaged, and that just wasn't going to happen in a room full of kids.
Seems to me the biggest problems children have in school are often directly related to the setting -- and an inability or unwillingness to conform, which ... I don't know ... makes it hard for them in public schools but might ultimately be the basis for their finer traits as adults.