I opted for the simplest form of trick there is – 'knock and run' as we used to call it in 1970s Timperley, or 'knock-down Ginger' as some southern fools insist on calling it. So in this version, I would knock on someone's door and leave a treat. I had very little time, as we were going away, so I bought a couple of nice things to eat and drink and chose my victims, who I can't reveal. One of the houses has a glass door and no cover for sneaking up or away. I crawled in and put down the treats, then knocked hard, slammed myself into reverse crawl, and got up and legged it round the corner. They would have had to be looking out of the window at that exact moment to spot me. Next morning a car stopped next to me and the two victims got out and gave me a big hug. 'That means a lot,' one of them said. It was unexpected and a sweet moment. One of them had been looking out of the window at the exact moment, and glimpsed my blue jumper, which I still had on. I didn't have time to explain that I'm not actually kind, but was just doing a challenge. It showed me that tiny efforts like this can be quite powerful – I'll try to keep dropping them in randomly when I see the chance.