You can't fix people, but you can fix a person. It's the same as saying you can't create a usable UI that allows any possible data to be entered, but you defini

You can't fix people, but you can fix a person. It's the same as saying you can't create a usable UI that allows any possible data to be entered, but you definitely can create a usable UI for some specific data. So the reason you've come to the conclusion that fixing people is impossible is because you're trying to fix everyone at once, and each person needs their own solution. Even better, some people don't even need fixing. Devote your time to just a few people and the problem disappears.