Perspective is a powerful force. From a young age we are taught to hold certain expectations, and those expectations influence how we see the world.
Stereotypes inculcated in you when you were a child may be affecting how you evaluate other people and even how you evaluate yourself.
Nobody rationally chooses to limit their aspirations, deny themselves opportunities, and misjudge other people’s talents based on a set of stereotypes. But that is just what we do without even thinking about it because stereotypes alter our view of the world.