why do you feel like dying when you wake up from a long nap but great after a good night’s sleep?

Piggybacking : Why am I drenched in sweat if I nap in the afternoon? Even at a steady room temp.

I think it has to do with interrupted remember cycles. If you sleep I hours normally, you have like 2 rem cycles. If you wake up at 4 hours, you are at the peak where you’re almost awake and feel ok. If you wake up at 6 hours, you interrupted a cycle and probably feel worse than if you slept for 4. The same may be true of an hour nap to a degree

Throwawayunknown55 is pretty right.

You have different levels of sleep: REM, light, and deep. REM sleep is where you dream and there’s a lot more that’s known and also being studied with that. Light sleep helps you recover physically while deep sleep helps you recover mentally. And you actually wake up multiple times

These levels are cycled throughout your sleep at different times and durations. Based on when you wake up, either from a nap or a nights sleep, will help determine how you feel when you wake up. Obviously if you wake up in an awake stage you’ll probably feel better. You can wake up in REM and still feel fine if I remember correctly. However, you wake up in light or deep sleep you’ll likely feel groggy and worse than before you took the nap.

Also, I think light and deep sleep periods are longer at the start of the sleep cycle than closer to the 6-8 hours that is recommended per night.

That’s the best I can remember but I hope it helped some. There is still a lot that we don’t know about sleep. I find it a really fascinating subject.

Source: some college courses while studying in health sciences

This isn’t as relatable as saying

Me when I sleep for 6 hours.

Waking up Tired ?

Me when I sleep for 12 hours.

Waking up Tried ?