Wouldn't innies lose their mind working nonstop?

That question bothers me for a long time. What could be the possible explanation for that? I'm not severenced but maybe they come out of the elevator more at ease after 8 hours chilling and 8 hours sleep? but for me that doesn't make a lot of sense, you still get back to the same stuff. In the world where Lumon severenced floor works as it should - they would just look at the screen with strange numbers not the whole day, but the WHOLE LIFE. I'd go insane