The habit started when he was seven.
A ball, thrown hard and long and with unforgiving inaccuracy by his father, was not retrieved from a neighbour's garden. His father shrugged, a fractional gesture that summed up the lowly value of the lost ball.
‘Shall we get that ice cream now?’ said his father, knowing full well what the answer would be. Though only seven years old and unable to define the word ‘bribe’, he realised the loss was incurred by his father's embarassed refusal to knock on a door and request the ball's return. He also speculated that any balls that sailed over fences or hedges might be imbued with magical powers. He was sure they gained a life of their own, became in some way free and were prone never to return. When he was nine Eileen Docherty moved into a house on his street, and he fell in love with numbers...