The longest I've stayed up was when I was 12 years old. I was at a friend's 12th sleepover party. Back then I was the kind of kid that got up at 7am every morning without fail, something that has only started to slide in recent years. So I got up at 7am that morning, went to the party and two of us - just me and one other kid - decided to pull an all-nighter and play Playstation. I believe the game was Gran Turismo lol. So we succeeded in that and I didn't even feel tired whatsoever the next morning. We spent that whole day together too; we were active as ever, we went to the park and did stuff and I didn't feel fatigued in the slightest.
The weird thing was though, that at about midday some weird crap started going down with my memory. Like, the guy who I had stayed up with all night... I couldn't remember his name or how we met or how he came to be in our friend group - it was like this weird memory void where I was like "who is this guy anyway?" I knew that he went to my school, but that was all I could place. Other than that though, I felt fine.
Then at 5:30 my Mum came and picked me up and took me home, and within minutes I fell asleep on the couch. Which makes the longest I've ever stayed up 34.5 hours. My Mum freaked the hell out when she saw me asleep on the couch - something I would never ever do no matter how tired I was was fall asleep before bed time. I was always the first up and the last to sleep. She frantically called my friend's Mum and asked if I'd been drugged lmao.