We've already established the difference between the Real and the unreal; now let's see what happens with that.
The Real is unalterable, unequivocal, and eternal. It is the Truth, not your truth.
The unreal is everything that is alterable, has opposites, and involves judgments, perceptions, and interpretations.
Are you starting to see?
The Course teaches it this way.
…it establishes a clear distinction between the real and the unreal (that which God did not create), between Knowledge and perception.
Knowledge is governed by a single law: The Law of Love, or God.
The world of perception (which is the world you see with your eyes, hear with your ears, etc.), on the other hand, is the world of time, of changes, of beginnings and endings. It is based on interpretations, not on facts.
Why does Jesus say "not on facts"? Because for him, a Fact is something that lacks interpretation; it is eternal. Who does this remind you of? Think, think. That's right! God! God is a Fact. Here, in this world, we have situations, and regarding the same situation, depending on the person, there's an interpretation; but it's their interpretation, and since they believe it to be true, for them it is. And it may not be true for you. And each person defends their belief, that is, their truth.
Are you beginning to understand what Jesus is teaching us through A Course in Miracles?