P-p-pick up a pebble. Feel its weight in your palm. Roll it over under your thumb. Any good? Not sure? Shuck it back on the shingle. Plenty of fish in the sea and more pebbles still on the shore.

In The Pebbles on the Beach: A Spotter’s Guide, Clarence Ellis, pebble-spotter par excellence, opens with the words: ‘Most people collect something or other: stamps, butterflies, beetles, moths, dried and pressed wildflowers, old snuffboxes, china dogs and so forth.