All I know is that is one of my wife's favorite sayings
I only use that term in response to people who refuse to take any responsibility for making a decision and leaving everything up to me but then criticize afterwards, That and a few other choice terms.
When you feel like a disappoint,it's the perfect thing to say.
Sometimes, it must be said because people put you on a pedestal. A very high one. For really...no reason at all. You have to remind them you're only human.