I've told this one before on AB. My daughter (then aged about 8 or 9) found a £20 note in our local shop and handed it in to the shop's owner, who praised my young 'un for her honesty.
Dad, however, took a different viewpoint and explained to his naive daughter that the money was probably lost by a customer but that it was now in the owner's till. Next time she finds any money, she should hand it to dad.
FF a few weeks, same shop, she finds another £20. This time she brings it home, hands it to dad who rewards said daughter by giving her £1.
The moral of this story is that honesty is not always the best policy. Obedience to one's parents is.