This great thing my Dad once did.

I just remembered this great thing my Dad once did.
I was at college at the time, and during the holidays I used to come home.
When the holidays were over, my Dad drove me to the airport.
As I got out of the car he produced several notes and handed them to me.
I said, "Dad, I don't need any money."
He said, "Well you can give me it back the next time you see me."