Sadly, some people are a few fries short of a happy meal.
A few beers short of a six pack.
Knitting with only one needle.
Lights are on but nobodys home.
The cheese slid off his cracker.
If you give him a penny for his thoughts youd get change back.
If you stand close enough to him you can hear the ocean.
etc, etc, etc...
I found this one to be highly disturbing:
This one is actually funny:
And this one is just too wierd: