A man walks into a bar and orders a beer. As he's sitting at the bar, he notices a sign that reads, "Free drinks for anyone who can make the horse laugh."
The man thinks to himself, "Well, why not give it a shot?" So he asks the bartender about the sign and the bartender points to a door at the back of the bar that leads to a room with a horse in it.
The man walks into the room and starts telling the horse jokes, doing silly dances, and even making funny faces, but the horse just stands there, stoic and unamused.
Feeling defeated, the man walks back to the bar and tells the bartender, "I give up, that horse is impossible to make laugh."
The bartender chuckles and says, "Oh, that's because you were in the wrong room. The horse in that room is deaf. But hey, you still made the dog giggle, so your drink is on the house!"