I might have said, Don’t pass up any chance to fool around with elephant dung. I’m thinking of what happened in the Laetoli valley in Tanzania in 1976, when a couple of young archeologists in a team led by Mary Leakey were horsing around with dried clumps of elephant dung. Ducking a flying pellet, Andrew Hill found himself prone above three sets of footprints. Closer inspection proved that they had been preserved in volcanic ash, hardened by rain to a cement-like consistency, at least 3.6 million years ago. The way the big toes were set parallel to the others, and the evidence of a “heel-first” mode of walking indicated that the prints were left by proto-humans rather than apes. Mary Leakey was moved by the discovery that the female in the trio had paused in her journey to look towards the left – perhaps to check on the child who was walking in her steps, or to scan for danger, which might include the plume of an active volcano.

So many great discoveries have their origin in play. The best work, by my observation, is done in a spirit of play. This requires us to forget the consequences and do what we are doing for its own sake. You may not find the Laetoli Footprints, now regarded as one of the greatest discoveries in the history of archeology, every time you fool around with elephant dung but – hey – it’s odor free and (nicely dried) a great substitute for a beach ball.