Sleep Paralysis is a fucking bitch. I know loads of people that get it and I also know lots that don't. I even know some people who enjoy it because then they can go into Lucid dreaming and do weird shit, those people tend to live in Brighton. Anyway, sleep paralysis in Alice terms is basically when your asleep and you feel either a presence at the end of your bed or pressing on your chest. You think your awake and you try to speak/sit up but you can't; your body's completely locked down (because your dreaming but you obvy don't know this.) It's highly unpleasant and can last from seconds to minutes, some have been recorded to go on 'for hours which is what I'd imagine similar to a coma.You do get a great work out though from all that tensing you were doing when you were trying to sit up and talk to the weird woman with the talking cat at the end of your bed...My definition is poor so wiki it because it's real interesting.