Twenty-year Jokes

Angus McClod walks into a bar and asks for a bottle of forty-year old Scotch. The bartender, not wanting to go down to the basement and deplete his supply of the rare and expensive liquor, pours a shot of ten-year Scotch and figures that his customer won't be able to tell the difference. Angus downs the Scotch and says: "My good man, that Scotch is only ten years old. I specifically asked for forty-year old Scotch."
Amazed, the bartender reaches into a locked cabinet underneath the bar and pulls out a bottle of twenty-year old Scotch and pours the man a shot.
The customer drinks it down and says, "That was twenty-year old Scotch. I asked for forty-year old Scotch."
So the bartender goes into the back room and brings out a bottle of thirty-year old Scotch and pours the customer a drink. By now a small crowd has gathered around the man and is watching anxiously as he downs the latest drink.
Once again Angus states the true age of the Scotch and more...