Did you ever watch children yelling at each other on the playground? One says “it’s true” the other says “it isn’t”. They don’t only say it, they truly believe in it. You maybe laugh at them and define this behavior as belonging to children.
Did you ever watch adults in a meeting room, at the tennis court, in a bar, or at the dining table arguing about a certain topic? One believes certainly that he is right, while the other is so sure about herself that she is right? They both are fixed in their viewpoint.
So who is right?
Both! It’s pretty simple!
Take a mug with an ear. Observe it carefully define it and place it on a table. Now ask people who sit opposite each other what they see. They might answer, a mug. Now ask them to describe what they exactly see without touching the cup or changing their seating position. Person X might say I see a mug with a drawing on it. Person Y might say I see a white mug with an ear. They look both to the same mug.
Who is right?