system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How is it possible to have dreams where we believe in completely impossible things until we wake up?

EDIT: Well this kinda exploded whilst I was dreaming about having a post explode...
gpt
One part of your brain (prefrontal cortex) isn't as active during sleep, this part is the part of your brain that decides if something is possible or not. So when you dream your brain isn't checking if the images are real or not.