Robin came home from her first day commuting into the city. Noticing that Robin was looking a little peaked, her mom asked, "Honey, are you feeling all right?"

"Not really," Robin replied. "I'm nauseous from sitting backward on the train."

"Poor dear," the mom said. "Why didn't you ask the person sitting across from you to switch seats for a while?"

"I couldn't," Robin replied, "there was no one there."