Social norm is a powerful catalyst to change people. It can be used to manipulate our will, belief, and habit.
Imagine living in a town where everyone worships a tree. You found it laughable at first, but over time, you begin to follow what others do and question your own ideology.
Our desire to fit in is so strong that we won't mind losing our identity. We would rather be wrong to fit in a group than be right on our own.