7 years on top
When you are asleep there is part of your brain that stays awake. No matter how asleep you are it is awake. Except sometimes when you are deep asleep you stop breathing. for up to a minute at a time. Or at least some of us do.
I've never woke up choking or in any discomfort tho. But, I believe it can kill you, if you were lying face down or had covers over your face etc...
I've had the sleep paralysis thing too, once or twice, that is quite scary.
& You can choke on your own tongue, I'z a qualified 1st aider and it's one of the first things you check for if someone ain't conscious / not breathing.