

It may have been real, in part of the shame for the family of having a family member deemed crazy. That family may have thought this was the best way to treat him, in part because the greater community wouldn’t accept him and there wasn’t any available treatments for them.
Now, it doesn’t mean that you have the same issues of the person in the story. Your mother’s village probably didn’t have an ability to differentiate people outside of sane enough to work and not. But, in her mind, she probably doesn’t have any ability to understand mental illness so this is the closest she can go to when discussing it.
And it is really hard to bridge that gap in knowledge.

I have a collection of masks. I assume others are like that too.