Having fun in supermarkets:
- Walk around the store and pick up exactly $20 worth of beer/liquor, plus a jar of baby food/pack of diapers.
- Approach the checkout clutching a $20 bill in your hand.
- When they ring everything up, look puzzled for a second, then pick up the jar of baby food/diapers and say “ah, I guess I’ll just put this back then”.
- Watch their faces.