Spotlight effect
The spotlight effect is overestimating how much other people notice your appearance, mistakes and behavior. Because you are at the center of your own world, you assume you are at the center of everyone else's.
In everyday life
Someone spends a whole party worried about a small stain on their shirt that nobody else noticed.
You stumble slightly on the stairs at the train station and spend the whole ride home cringing, sure that everyone on the platform is still thinking about it.
Why your mind does this
Social life depends on guessing what others think and feel. Using our own mind as a model for other minds is fast and often roughly right, because people share a lot. It let our ancestors predict friends and rivals without needing to ask.
How to spot it
Ask how much attention you would give the same small slip if someone else made it.
How to counter it
Remind yourself that most people are busy thinking about themselves, and test it by asking a friend what they actually noticed.