At one point in college I stayed awake consistently for 4-4.5 days without any caffeine or other stimulants. By the second/third day the feeling of being "tired" was entirely gone, and I felt energetic and almost intoxicated. There was definitely euphoria, as well as some auditory/visual hallucinations. Afterwards I slept for about 20 hours straight. It was an odd experience
I managed 53 hours once over a weekend of a big LAN party, drove home and slept for 26 hours after that. Apparently my mother called the doctor who just said to check I was still breathing and that I'd probably wake up soon.
I woke up thinking it was Monday but it was Tuesday. That took some explaining at work.
Felt amazing after about 30 hours of being awake and after the sleep's "jet lag" wore off.
I had a similar experience after a week long camp where I only slept a couple of hours a night, if that. On returning home I went to sleep and distinctly recall waking up about an hour later, only to discover I'd actually been asleep for ~25 hours.
I never experienced euphoria then, but in my younger years when I could still successfully pull all-nighters I found myself re-energized once the sun rose in the morning and this lasted typically until later that afternoon. This lead to a general rule where if I was planning on staying up that late I always tried to go to bed before the sun came up.
Obviously I am not recommending that anyone try it without medical supervision, but people should at least know that it's an option.
1. https://www.scientificamerican.com/article/why-sleep-depriva...