I can relate to a number of these - in particular remove contact lenses BEFORE chopping chillies!

A good trick to pull on team members who always turn up late is to anoint their jockstrap with a small amount of Deep Heat (or similar) - they tend not to notice until they start to warm up unless you overdo it. The results are particularly funny in a rowing boat!

I also was a terror as a child - the worst was the mixture of red phosphorus, magnesium powder and potassium chlorate - I lost a lot of skin to that one and was very thankful that I wore glasses. Another time we made nitrogen tri-iodide and sprinkled a little behind the Chemistry master's desk - he walked in to a 21 gun salute from his feet.