When I was a small child growing up in Bristol, my brother, sister and I used to walk to the bus stop from our school. I would sit on a low stone wall and stare at the Monkey Puzzle tree in the garden across the road and imagine a monkey trying to find its way through the maze of branches to the centre, retracing its path whenever it reached a dead end. This kept me entertained during the tedium of waiting – when I wasn’t picking up bits of chewing gum stuck to the wall and popping it in my mouth (to the disgust of my siblings who made me spit it out). We weren’t supposed to be at this bus stop. My brother and sister had the cunning plan of walking down the long steep hill each day to save on bus fare so we could spend it in the sweet shop at the other end. Cunning, until one afternoon my mother asked me what I was chewing and the truth was regurgitated as quickly and easily as the used gum and I gleefully explained that we spent our change on sweets every day. The following week we were catching the bus from outside the school with a blank wall opposite to entertain me.