Growing up, I was given worksheets with a list of statements, and the assignment was to correctly label each statement as a fact or opinion. For example, the statement “Chocolate is the best flavor of ice cream” required the opinion label, while “Water freezes at zero degrees Celsius” is most definitely a fact. My students tell me that this instruction continues, and I have found that “the ability to differentiate between fact and opinion statements” is still in the curriculum. There is another place this course of instruction happens: prison camps. Why? It is a thought stopper — once a statement has been identified as mere “opinion,” then there is no more discussion about whether or not it is true. So, what does opinion mean when used in this way? Roughly, an opinion is a statement that is not really true or false; it is just what someone thinks and what someone has the right to think because they can believe what they want.
Fact Versus Fiction — the Indoctrination of Relativism| National Catholic Register