It would be nice to be able to know if this really happened:
After a day at the races in England, a friend told Mark Twain, "I wish you'd buy me a ticket back to London. I'm broke."
Twain told him he couldn't afford two tickets but proposed that his friend sneak aboard the train and hide under Twain's seat. Then he bought two tickets anyway.
When the train had got under way, the inspector appeared to collect Twain's ticket. When Twain gave him two, he looked about the compartment and said, "Where's the other one?"
Twain pointed under his seat, smiled, and said, "My friend is a little eccentric."