Slightly off-topic: I've noticed if I work all night (e.g. yesterday writing a paper proposal for a conference), and I manage to stay up all the way until dawn,

Slightly off-topic: I've noticed if I work all night (e.g. yesterday writing a paper proposal for a conference), and I manage to stay up all the way until dawn, I literally get euphoria once Sun glances through windows. I can be super tired, but it shots my mood up considerably.