In a vignette with Azul Silver confides that he has had difficulty getting students at Diasomnia to listen to him, and Azul spends three hours teaching him how to sit, rebuke others, shake hands and present himself to be properly intimidating and project an air of authority.
Sebek appears at the end of the vignette and Silver attempts to reprimand him for his usual rudeness by forbidding him access to Malleus until he can fix his attitude.
Sebek does not react well, and it is revealed that the reason students are not listening to Silver’s orders is because he falls asleep mid-conversation.
Silver seems confused by the thought that people think he gets sleepy when he tries to study, but he then immediately falls asleep during a lecture by Jamil.
When Deuce is evasive in response to his mother asking about his studies, Silver wonders if Deuce also falls asleep during his classes.
Silver also falls asleep during the Rabbit Run event at the White Rabbit Fes, falls asleep in a hallway during Fairy Gala, falls asleep on Main Street after Fairy Gala and falls sleep while sitting on a water fountain in Fleur City.
We also see Silver fall asleep during one of Crewel’s classes and in response to Lilia playing on an electric guitar in an attempt to wake up his tsum.
Rook says that if he were to choose anyone at NRC to be on a deserted island with him he would choose Silver precisely because of Silver’s ability to fall asleep anywhere, and “Sleep is essential to keeping up one’s health and remaining active, more so in an unknown land. The ability to sleep whenever and wherever is a critical weapon in the quest for survival.”
Kalim says that Silver will fall asleep mid-conversation in class and in the hallways, and he recently fell asleep during a potionology assignment.
Twisted Wonderland Reference Note 