Yes, staring is rude, I get that. But you have to understand, our brains are hardwired to stare.
Pattern recognition is so innate that when we perceive something that breaks the expected pattern our first instinct is to keep looking at it until we understand what we're looking at. It's unconscious, and if we're lucky we'll catch ourselves doing it to a person and try to mitigate the circumstance with shifty glances elsewhere, but our eyes will always be drawn back as soon as our concentration wavers.
Pattern recognition is so innate that when we perceive something that breaks the expected pattern our first instinct is to keep looking at it until we understand what we're looking at. It's unconscious, and if we're lucky we'll catch ourselves doing it to a person and try to mitigate the circumstance with shifty glances elsewhere, but our eyes will always be drawn back as soon as our concentration wavers.