In The Holy Bible  we read:
When I was a child, I spake as a child, I understood as a child, I thought as a child: but when I became a man, I put away childish things.
I have no idea whether this guidance is to be taken literally but, if so, and if I was a Christian believer, I would need to think twice about the enjoyment of games that adults are meant to have “grown out of”. One of the many pleasures of becoming a parent is that we can legitimately enjoy these games once again as our children grow up.
One that I still play is Poohsticks, described by A. A. Milne in The House at Pooh Corner  and demonstrated in a wonderful drawing by E. H. Shepard of Christopher Robin, Pooh and Piglet playing the game (see above). As is now well known, Poohsticks is for two or more players, each of which selects a stick. On command, each player drops their stick into a river from the upstream side of a bridge and the first stick to appear on the downstream side of the bridge decides the winner.
Last week, I was walking on Boxmoor in Hertfordshire where a bridge crosses the River Bulbourne and, as on other occasions, the child in me could not resist playing Poohsticks. Necessarily, I played against myself and took two twigs and threw them in to the water and I didn’t much care which one came out first as I was the winner anyway. Both twigs eventually became tangled up, together with other vegetation, on a small tree trunk that had fallen across the river. While watching the fate of the twigs, I also notice that a submerged horse chestnut leaf was being carried downstream, but it was moving slowly compared to the twigs. As someone who spent a career looking in streams and rivers, I already knew that there are many methods by which vegetation becomes trapped, and thus retained to provide nutrients after decomposition, and I also knew that water flows more rapidly at the surface than in the water column (illustrated crudely below: higher in the water column the influence of friction from the bed becomes less).
Playing Poohsticks, in addition to allowing me re-entry to the joys of childhood, resulted in observations and questions for which I was able to provide answers based on acquired knowledge. When conducting original research, it is always helpful to ask questions like those inspired by child-like curiosity and I admit that there were several occasions in my career when I had the “look at that!” or “what’s that?” response that one might expect of a five-year old. The result was sometimes questions that could be framed into hypotheses and null models that were testable (using the best Popperian method), although I was always aware that complex biological systems have probability at their core, rather than just the absolute laws of physical science.
The main lesson to come from all this is that I Corinthians 13:11 must not be taken literally and we should all be child-like in the best sense, not like the childishness of Mr Trump that has recently grabbed the headlines . Being child-like keeps us open to serendipitous discoveries and, as we know, many of those “accidents” have led to important steps in understanding the world around us. I always encouraged students to be child-like and to be amazed, and thrilled, by living organisms and their way of life. I can't help it.
 I Corinthians 13:11 in the Authorised King James Version of The Holy Bible.
 A.A.Milne (1928) The House at Pooh Corner. London, Methuen. (My edition was published in 2004 by Egmont U.K. in London).
 Michael Wolff (2018) Fire and Fury: Inside the Trump White House. London, Little, Brown.