Ever wake up only to feel that there is a large, uninvited presence behind you? You could be right or you could still be dreaming.
Either way, it’s probably best just to fall back asleep and hope that it doesn’t snore or slobber.
Do you need a long, uninterrupted nap? Find a pillow that matches your fur and curl up there. Your pillow camouflage will make you all but invisible to humans who have an annoying habit of skritching your ears and disrupting your dreams just when you are about to catch a bird.