

You might be interested in trying a polyphasic sleep cycle. Instead of one big 8 hour sleep each day, you could try two 4 hour sleeps. So, you can have your middle of the night sleep, and maybe another one after you get home from work or eat dinner or something.
Supposedly polyphasic was pretty common prior to the industrial revolution. Nothing really wrong with it if your schedule can accommodate it.
Only place I’ve occasionally run into metric prefixes above km is in astronomy within proximity to our planet. You just don’t need them for most terrestrial applications, and as soon as you get out of the solar system people switch to parsecs and light years.
I suppose people also have a basic sense of how long a km is, where that goes out the window with anything bigger. Especially anyone who has gone through the military, has an intuitive feel for how distant a “klick” is.