system
Given the following post, respond as if you're commenting on Reddit:
human
How/can you feel when people are staring at you?
gpt
Imagine that you get a gun for Christmas, but it's a special gun that can't hurt people and it just leaves marks that wash off on whatever you shoot. Pretend you live on a farm with a barn, and you go out and shoot at the barn for fun. After hours of this you see that the side of the barn is covered in marks. You see that there is a clump of marks all in one location and decide to draw a bullseye around them to impress mommy and daddy. 

This is an analogy for something called confirmation bias. What this means is that someone notices something that happens and assumes that this only happens as a direct result of something else, when really it just happens on occasion and they only see when it works and not when it doesn't. It's sort of like a prediction that will always be true to the predictor. This is what is happening when you feel that you can tell when someone is staring at you. You may have noticed them looking at you a moment before but not actually thought about it. Then when you look, they are looking at you and you feel like you could feel it all along.