What’s the science behind someone being a “light sleeper”?

Question

What’s the science behind someone being a “light sleeper”?

In: Biology

Answer 1

I think it has to do with what your brain reacts to in your sleep, partially learned/trained from habit. Personally I can sleep through all my alarms, but I take care of a relative alone, so if they call out I’ll wake up immediately. Your ears are always listening anyways.