Pwest is a term to describe someone who is quite smart but does silly things, often at their own expense.
By snatching for that pen you actually knocked your full glass of beer all over the table and smashed it on the floor. Good one Pwest.
Those straps on your golf cart are to stop the bag from falling off onto the ground. When you refuse to do them up your bag falls off onto the ground.
You silly Pwest.