Working overnights can take a toll on one's psyche. When you're predominantly spending you're only waking hours in the dark, life can get a little draining. Aside from that, the wee hours of the night also come with surprises. There is a reason that most horror movies take place after the sun has set, the night comes with some chills and spooks. And yes the kooks love to run amok under the moon. So working the night shift can leave you a bit shook now and again. Shook, like Stephen King shook.