Because it stops your tongue from lolling.
My 14 year old daughter hangs drawings on her wall that her friends have drawn for her. I noticed a new one that looked like a building with a light on it. I asked her who drew the building. She said "my friend Eilene did and its supposed to be a Tardis."
I quickly replied "it looks like a retardis to me." She rolled her eyes and grinned. I laughed for 5 minutes after leaving her room.
My wife groaned, my son laughed and covered his face. Seems like a success to me.
We can't mention the fact that someone's deaf without my Dad responding 'pardon?'
As a child I would repeat myself endlessly as he lolled inside.
So my friend and I were both college freshman and I'm going with him and his uncle on the first day for lunch. We pass a Chase Bank and his uncle says "you an go to Chase bank of you need to get money" My friend, "it's a bank, why do I have to chase it?" I lolled right out of my chair