For this lithograph, Dalí took inspiration from ‘The Portrait of Luca Pacioli’ – a painting attributed to the Italian Renaissance artist Jacopo de' Barbari, dating to around 1500. Pacioli was an Italian mathematician, Franciscan friar, and collaborator with Leonardo da Vinci. Dalí used Pacioli's likeness and added his surrealistic imagery, creating ‘The Hermit’ tarot card and this work, Mystery of Sleep. The man's face has been replaced with a melting watch, one of Dali's most memorable symbols. Time seems to move differently when you are asleep in a dream state – almost fluidly. Dalí portrays the watch to be melting to demonstrate this fluidity of time. The man is wearing a crown decorated with jewels, flowers, and egg-shaped adornments, all known to symbolize fertility, abundance, and new life.