A man has to attend a large convention in Chicago. On this particular trip he decides to bring his wife. When they arrive at their hotel and are shown to their room, the man says, "You rest here while I register. I'll be back within an hour."
The wife lies down on the bed. Just then, an elevated 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. Again a train shakes the room so violently, she's pitched to the floor.
Exasperated, she calls the front desk and asks for the manager. The manager says he'll be right up. The manager (naturally) is skeptical, but the wife insists the story is true.
"Look, lie here on the bed. You'll be thrown right to the floor!" the woman says.
So he lies down next to the wife. Just then the husband walks in.
"What are you doing here?" the husband asks.
The manager replies, "Would you believe I'm waiting for a train?"