What's the difference between working all night until 4am and waking up at 12pm and going to sleep at 10pm and waking up to work at 5am?
Being an 'owl', I usually go to sleep at 11pm-1am, but very rarely, I wake up early (e.g. 5am) and feel kind of a euphoria and rise of productivity, which lasts until afternoon. Is there any medical reason for that euphoria?