Why is it harder to get up when forced to wake up?

Question

I only noticed this for quite a while now but never considered it much of a problem but I noted that when I'm forced awake (i.e. someone wakes me up) I feel significantly drowsier versus when I wake up of my own volition

For example, if someone were to forcefully wake me up around 10 AM, I would feel pretty groggy and cranky yet when I wake up by myself at around 4 or 6 AM I actually feel 'awake'.

Answer 1

When you are forced to wake up, you've interrupted your body's circadian rhythm. If your body is used to waking up at particular time and you're woken before that time, you'll still feel very tired. Because to your body, you're still meant to be sleeping.