"Circadian: relating to biologic variations or rhythms with a frequency of 1 cycle in 24 ± 4 h; circa (about, approximately) and dies (day or 24 h)." Why yes, he's memorized the official definition of that term; what he says next is rote from someplace else as well. "Circadian rhythms are physical, mental, and behavioral changes that follow a 24-hour cycle. These natural processes respond primarily to light and dark and affect most living things, including animals, plants, and microbes."

Then, César adds himself: "Sleep-wake cycle, in this case. With the proliferation of artificial light in my time, it's very easy to get lost in one's work and stay up far later than before rapid electrification. Our artificial light is strong enough to disrupt our natural bodily rhythms."

Which absolutely had nothing to do with keeping himself distracted until he was literally too tired to think about one of the most traumatic experiences in his life that just happened. Nope. Absolutely not.