In laboratory settings, when humans are deprived of the neon circus of modern lighting and forced into old-world darkness for 14 hours a night, they spontaneously drift into the same pattern: two sleep chunks with a quiet period in the middle.
I freak in pitch black darkness so I sleep with the TV on. That being said I usually wake up for a couple of hours and actually watch the thing until it puts me to sleep again. Naps work when I need them... modern age, primitive, old thing that I am.