I was standing in a chip shop queue the other day when a guy started handing round a tube of parma violets. He'd just sent his daughter to the sweet shop next door to buy them and was extolling their virtues. I took one and slipped back 50 years. They tasted just as I had remembered them.
I didn't notice any alteration in the nether regions, but then a lone parma violet would stand no chance lol.