On vacation, a man and his wife check into a hotel. The husband wants to have a snack at the restaurant, but his wife is extremely tired so she decides to go on up to their room to rest.  

She lies down on the bed... just then, a train passes by very close to the window and shakes the room so hard she's thrown out of the bed.  

Thinking this must be a freak occurrence, she lies down once more. But just a few minutes later a train again shakes the room so violently, she's pitched to the floor.  

Exasperated, she calls the front desk and asks for the manager who says he'll be right up.  

The manager is skeptical but the wife insists the story is true.  

"Look... lie here on the bed -- you'll be thrown right to the floor!" So he lies down next to the wife.  

Just then the husband walks in. He takes one look at the manager lying in bed with his wife and yells, "Hey! What are you doing in here!?"  

The manager calmly replies, "Would you believe I'm waiting for a train?"