Fortune tellers never tell their own fortune, doctors don't treat themselves, and people can't face their hearts no matter how smart they are. What does this passage mean?

First of all, fortune tellers know their own lives before counting others' lives; If the surgeon cuts his hand with a knife, won't he dress himself? Is it possible? Of course, this passage is chicken soup for the soul, so there is no need to delve into it.

It means that it is difficult for people to make objective and fair judgments when facing themselves!