The most notorious example of the mind-distorting effects of solitude is the case of Donald Crowhurst, who took part in a 1968 race to become the first solo sailor to go non-stop around the world. From the race’s outset, Crowhurst ran into problems with his boat and, faced with the prospect of returning home a failure, he sailed aimlessly around the Atlantic while sending back false reports of his position.

Fearing financial ruin and overwhelmed by the scale of the subterfuge, he cut radio contact. His boat was discovered floating in the Sargasso Sea months later. Crowhurst was nowhere to be found, but a 25,000-word diary discovered on board detailed the Englishman’s descent in to madness.

During one visit to Virgil, I found the door to his cabin open and Virgil passed out at the table, an empty liquor bottle beside him. Afraid of his reaction if he suddenly came to and found me there, I went outside and knocked hard till he stirred. When he finally emerged he stared at me like I was a ghost.