Here’s proof that one can be sceptical in a dream.
I was in a class of little children. We were playing this video game that demonstrated the food chain.
I started off controlling a mouse. It was quickly consumed by a cat.
So now I was controlling a cat.
I then had to dodge a scary looking dog, but managed to lose him. See? I always knew cats are more intelligent that dogs! 
Next challenge was in the form of a bird.
The cat managed to kill the bird. So, now I was in control of a bird?
“Stupid game..” I thought.
The bird spied a rat and quickly gobbled him up.
Now, yes. I was a rat.
Guess what came to eat up the rat?
A GIANT rat..
“This game sucks!” I whined “There’s no such thing as a giant rat!”
So, the teacher opened her cupboard to reveal that, in fact, giant rats do exist...
Surprisingly, I didn’t wake up screaming!