6. Eat Yoghurt Out Of A Mayonnaise Jar
Warning: this one is pretty immature. However, it is also hilarious if pulled off correctly. The set-up is simple, even for a prank as childish and silly as this, and while the idea of filling a mayonnaise jar - washed out and sterile - with your favourite plain looking yoghurt might not seem like a silly way to bring delight your day, it's a harmless prank in which no one gets hurt, no one gets embarrassed, and which you'll be able to have fun with people whilst giving yourself a big boost. For full effect, really make a deal of it: tuck in with a big spoon, hum your enjoyment, and watch as those nearby start to react in horror. You can let them in on the joke as and when you like, but it's silly, immature, and something everyone should try at least once.