Do you have any good-natured pranks you pull on family, friends, etc.?
Last year I planted some corn seeds in my friend's garden and he faithfully watered and fertilized them when they started to pop up. Obviously he isn't from a farm background as he kept raving how big his new 'Cannas' were getting. We had a good laugh at the big corn stocks coming up among his real cannas and dahlias. We were all profuse in our praise of his green thumb and only when the ears appeared did he get the joke.
This was in revenge for the big plastic spiders he strategically hid around our garden the year before. Just enough so we'd come across one every couple of weeks and jump out of our garden shoes.