I rent a snorkel and flippers on the island of Ko Tao in the Gulf of Thailand. Underwater it’s neon-orange, brilliant blue anemones, a squadron of silver minnows moving together in perfect formation. I drift over the edge of the reef and suddenly it’s dark below me. Deep. And then out of the darkness, something moves. The unmistakable side to side of a giant tail. A shark, circling slowly. That’s when I do the exact wrong thing: total panic, slapping wildly at the water like a spastic seal. This sad display continues until I crawl up on the beach, gasping for air, already starting to spin the story into a fearless encounter where it’s me and the shark, mono-y-mono, when I remember the trick of slapping his nose, and it works, the cowardly fish slinking back into the shadows, bested by the hairless plains-ape.