"Act of Generosity" joke

A woman was chatting with her next-door neighbor. "I feel really good today. I started out this morning with an act of unselfish generosity. I gave a twenty dollar bill to a bum."
"You gave a bum twenty whole dollars? That's a lot of money to just give away. What did your husband say about it?"
"Oh, he thought it was the proper thing to do. He said, 'Thanks'."