Going around and coming around

I was at the Phoenix Artists' Club last night (or, as everyone except the manager calls it, Shuttleworths) and noticed a ten pond note on the floor by the bar. I picked it up and asked the customers next to me and my friend whether it was theirs. They said no, so after a moment of consideration - do I keep the tenner, given my relative poverty - I handed it to the barman, feeling generally good about my moral health. And in a piece of instant karma, the barman gave me the two pints on the house.

So everyone wins. Except whoever lost the tenner in the first place...