What is a short summary of the story, Vanity, in the collection, There’s Something I Want You to Do: Stories?

Vanity, follows the character of Harry, who previously appeared in the story Charity. Harry works as a sales representative for medical devices. He boards a flight to Las Vegas to attend a conference for work. On the flight, he converses with the elderly man next to him. The man’s name is David Lowie, and he is a holocaust survivor. David is married and is going t Las Vegas on vacation with his wife. Harry is deeply moved by his conversation with David, and David gives his email address to Harry. Harry later sends David a friendly and sincere e-mail, but David’s reply e-mail is very brief and terse.