Why do people see/hear terrifying things during sleep paralysis?
I understand not being able to move and feeling like you can’t breathe, since your body is still in sleep mode. But why do sufferers so often see or even hear things that are so absolutely terrifying? Is it something to do with REM sleep? If so, why is it always frightening things? (I don’t know about other people, but my one experience with sleep paralysis scared me way more than any nightmare I’ve ever had, although that seems to be true for most from what I’ve read of others’ experiences.)