Two guys sitting at a table in a restaurant. Waiter comes, asks if he can take their drink order.
Guy #1 says, "I'm a chemist, so I'll just have some H20."
Guy #2 says, "LOL, I'll have some H20 too."
Waiter brings the drinks, they both drink, Guy #2 dies. Guy #1 calls him an idiot.
The End.