Wrong concept of fear?

Over the weekend Shawn overused the word "pahpah" and tapping his chest while he says it - it means scared in Mandarin. He would walk or run in the mall and then suddenly pat his chest and say pahpah. Or sometimes in the mall, when we pass side corridors leading to toilet he would pat his chest and say pahpah. Everytime he says it he's happily smiling away. I wonder if he's using it in the wrong context at the wrong time and wonder if he really knows what that word means.