Confidence isn't something that comes easy to a lot of us. And because it's difficult to feel at the best of times when you don't feel like you're doing well or failing it can be even harder to come(Little Step Quotes)
Quite possibly, this is the cruelest thing that you could do to someone. Particularly when you don't understand it or only know part of the truth (at best), anyway. Let people live; let people learn. (Those are not my words but well said.