Opinions:
Two people look at a cat and a dog. One thinks the dog is cuter. One thinks the cat is cuter. They agree to disagree. End of story.

Facts:
Two people look at a cat and a dog. One thinks the cat is heavier than the dog as it sits closer to them, appearing bigger. Person two says the dog is heavier, and it is. There is no "agree to disagree" here, only right and wrong.