Illusion of transparency

The illusion of transparency is a tendency for people to overestimate the degree to which their personal mental state is known by others.

Another manifestation of the illusion of transparency (aka the observer’s illusion of transparency) is a tendency for people to overestimate how well they understand others' personal mental states.

This cognitive bias is similar to the illusion of asymmetric insight, but the illusion of transparency is more prominent for people who have a personal relationship.