Your body oftentimes will turn off while you sleep so you don't start flopping around and kicking everyone's asses in your sleep and twisting your neck and so on. When your brain is awake but your body hasn't gotten the memo, that's sleep paralysis.

From my uneducated standing on the matter, of course.

If there's infinite alternate timelines, doesn't that mean an infinite amount of myself is dying every second of my life?