One of my first jobs was to keep a lookout for lions. There are some occupations that are not suitable for someone with untreated narcolepsy and this is probably one of them. I was 22, a recent zoology graduate studying meerkats in the Kalahari desert in South Africa. We worked in pairs, one of us on foot, walking with meerkats, the other in the jeep scanning the horizon for signs of leonine danger. On many occasions, I awoke with the imprint of the steering wheel on my forehead, realising that meerkats and colleague had wandered out of sight. I would look for signs of life and, as the panic grew, signs of death. I can tell this story now only because nobody got eaten.