A colleague of mine in a previous job had to take a month or so off because he'd banged his head and suffered a concussion, after which he walked home, refusing to go to hospital, and slept it off. He was among the most arrogant pricks I've ever come across. I'd tell people about him and call him "the pigeon" because he was so stupid but he strutted about with his chest out like he knew it all. I'd always felt a bit guilty for thinking he was stupid after his concussion, but one day it turned out a friend of mine had worked with him years ago, and no, he's always been like that. I suppose that he slept it off should've clarified it.