Also happens in the other way too, probably more often as the driver since you should have your eyes on the road more. But being in both spots, I’ve definitely felt eyes staring at me and looked to see them just staring in the mirror.
”Did I run a red light? Did they just ask me something and I zoned out and didn’t hear them? Did I just run over someone and didn’t notice? WHY ARE YOU STARING AT ME?!”