system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Teeth grinding at night and how it can be so loud. Also how can our jaws clench that hard unconsciously but not awake?

One night in college I heard my buddy grinding his teeth after he passed out. It was one of the strangest noises I have ever heard! Made me think of two massive blocks of concrete sliding together. How can our jaws make this much pressure when we are asleep. I can't clench anywhere near that hard when I try.
gpt
Your teeth are also capable of biting your finger off entirely, but when you're awake and aware, your brain does not authorize such a dumb idea as mutilating yourself. It's the same with teeth grinding. You are absolutely capable of grinding your teeth hard when you're awake, you're using the same muscles. You're just not aware that you're not actually trying as hard as you physically can.