Albert Einstein was traveling from Princeton on a train. When the conductor came down the aisle punching tickets Einstein reached in his vest pocket; he could not find his ticket, so he reached in his trouser pockets. It wasn’t there so he looked in his briefcase, but still could not find it. He looked in the seat next to him, but it was not there.
The conductor kindly said, “Dr. Einstein, I know who you are, we all know who you are. I’m sure you bought a ticket, don’t worry about it.” The conductor then continued on his way punching tickets. Just before he went to the next car he turned around and saw the great scientist on his hands and knees looking under his seat for his ticket.
The conductor rushed back and said, “Dr. Einstein, Dr. Einstein, don’t worry. I know who you are. No problem. You don’t need a ticket.”
Einstein said, “Young man, I too know who I am. What I don’t know is where I am going.”