It is for the same reason a child gets so much glee when she catches you out with a trick questions such as:
Q1: How do you get down from a horse?
Q2: I may have it (3)
Clearly the concealing and finding of clues is fundamental to human nature and people have a deep urge to create and solve puzzles.
This is not a modern phenomenon. Riddles, for example, permeate all cultures. History is riddled with them. The ancients held riddle contests much in the same way as we challenge each other over a pint to such lateral sophistries as:
Q3: What runs fore to aft on one side of a ship and aft to fore on the other side?
Perhaps the most famous classical puzzle of all time is the riddle of the Sphinx as solved by Oedipus.
Q4: What creature moves on all fours in the morning, on two feet at noon and on three toward the setting of the sun?
Why puzzles are engaging is a puzzle in itself. Aristotle puts his classical finger on a couple of important clues. First he opines that a love of riddles reflects the human tendency to make metaphor; second that they teach us something.
Man has evolved to be a problem-solver. Animals - particularly young ones - exercise, in play, skills that they will later use in earnest. Play provides a safe arena where the imperfections in skills such as chasing, scrapping or escaping do not lead to serious consequences. Young children running and clambering over climbing frames are practising their physical skills. Language, jokes and puzzles are merely the mental form of this activity - the intellect at play.
But isn't play for children? Shouldn't we grown-ups obey that spoilsport St Paul and put away childish things?
I think not. The world is perceivable in an infinity of ways and we can only handle it by categorisation. We view it through filters or, as neuropsychologists say, templates. As we age we get more rigid in our mental habits and it becomes increasingly difficult to see things in new ways.
In challenging the rigidity of our conceptual boundaries, puzzles not only rejuvenate and refresh, they also tell us a great deal about how we think and perceive, which is why they are of such crucial interest to educationalists, psychologists, mathematicians, artists - anyone interested in thinking about thinking.
What is it, for example, about the way we think that makes the following so counter-intuitive?
Q5: I know Bill has two children. He has told me that at least one of them is a boy. What are the chances that the other is a girl? - Well?
1. You don't: you get down from a duck.
3. The name of the ship. (Either that or a drunken sailor: probably the one whose use at our hands is so philosophically discussed in the sea shanty.)
4. Man: he walks on all fours as a baby, two legs as a young man, and uses a stick when old.
5. Two in three.
Chris Maslanka will be presenting "Puzzle Panel" - a new series on BBC Radio 4 beginning on Thursday 4 June at 1.30 pm, repeated Sunday 7 June at 11 pm.