Some of what you believe came from a rumor in sixth grade. Check the expiration date.

Beliefs get filed once and then stop being reviewed, so things you accepted at eleven are still sitting there with full authority. You were not checking sources then, and the belief did not update itself just because you got older. Most of it is harmless. Some of it is quietly shaping decisions you think you are making fresh.

Pick one thing you are confident about and try to remember where it came from. If the answer is a person at school or something you half heard, look into it properly now. Keeping it is fine, as long as you keep it on purpose.