[puzzlingcaptcha]

It's not unusual to feel good after pulling an all-nighter. Sleep is when re-uptake of serotonin takes place, so if you interrupt it you end up with a surplus. Although there are also other possible explanations [1]

1. https://www.pnas.org/doi/10.1073/pnas.2214505120

[taeric]

I'm assuming it is similar to the "runners high" people get at the end of a long run? You will feel very energized in ways that don't make sense. And if you don't force yourself to just lay down and pass out, you can keep going for longer than you would have thought. Will crash harder, though, if my experience is common.