Because not everything happen at once
Many groups experience prejudice and potentially all groups, even the majorities can experience prejudice.
However, Prejudice is most apparent in the case of minorities, such as racial, ethnic and gender minorities. For example the idea that women or people of certain nationalities are not as competent at work is a prejudice .
The code of conduct a knight was expected to follow was The Code of Chivalry. It was their highest moral system that wasn't just rules of combat, but introduced fine qualities such as bravery, courtesy, honor, gallantry, etc.
Recycling , taking care of are trees
