Why do we make horrible decisions?

And are happy with it

I have a friend who likes to share about his life.
The dialogue always ends with 
“I don’t get it.”
People around him make horrible decisions and never seem to realize it.
It reminded me of that passage from Cialdini’s Influence and Manipulation.
Tim and Sarah’s story. 
I’ll tell you the passage as I remember it, there might be some mistakes but the heart of…