I have had that. Not lately but there is nothing uncommon about it. When you feel like you can't move yourself in your dream. It happens often when you either have a lucid dream or you dream that you woke up. It's kind of weird. But yeah sometimes when you are dreaming about something and stuff doesn't add up (in most dreams stuff doesnt add up but we usually dont realize it), like if you dream about a dead relative and you are talking to him, once in a while you have the presence of mind to realize...."hey this is not right, this person is passed on, i must be dreaming." Which is kind of freaky because you know you are dreaming but you are still there in the dream which is not real. And sometimes its like you try to react or escape somehow and you are just like jello. Sometimes in those dreams, if you have them, you will experience a paralysis. And sometimes it happens when you dream that you woke up. That's a weird experience too.