system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is it sometimes really hard to wake up after you have slept for a long period of time? Shouldn’t you be well rested?

When I consistently sleep 8 hours I feel well rested and even alert when I wake up. But after sleeping 10 + hours I feel groggy as hell for ages after I wake up and it’s harder to motivate myself to do stuff. Shouldn’t you feel more rested the longer you sleep?
gpt
It’s less about the amount of time you are asleep for, and more about the quality of sleep and sleep cycles. During the night you are cycling from light to deep sleep.

If you are waking up in the middle of a deep sleep, you’ll feel groggy as hell, whereas if you wake up during a light sleep, or wake up naturally, you’ll feel well rested.

I used to use an app that tracked movement during the night and would wake you up during your lightest sleep in an inputted window of time, maybe you could benefit from a similar app?