Eli5: why do we sometimes wake up in a really bad mood after a mid-afternoon nap?

Question

This is something that happens to me from time to time since I was a kid.

I would take a nap after lunch, on a day like today. Then sometimes wake up feeling disoriented and depressed. Other times I’d feel fine.

What causes this specifically and why does it only happen sometimes?

In: 183

Answer 1

Are you waking up naturally from the nap or are you being woken up? For me it makes a difference – if I wake up naturally I generally just feel rested – but if I’m woken up, my mood seems to depend on where I was in the sleep cycle.