The stories we make up in our head often don't resemble reality.
We can convince ourselves of anything we want to. If we decide to believe a thought, usually based on zero proof or evidence, and we choose to give that thought energy, then the mind will gather as much information as it can to back that up.
It's not the mind's fault, that is what it is programmed to do. To all intents and purposes, it is a computer that cooly, and often cruelly and mechanically, will sift through the world slicing it up into pieces of information that will prove its point. The ego loves being right and the mind is its humble servant. Yes master, anything you want master.
But, what we are left with is a version of the world, a story, and not an experience of the real world. And, then these stories play around inside our heads like broken records. And we wonder why we are often so exhausted, so frustrated and so isolated.
The mind can always make 1 + 1 = 3, if we ask it to. The better question might be to ask why we would prefer to settle for a story about reality rather than the truth.
But, in order to let go of this story we need to be able to see that that's what we are doing. We need to admit that our stories are just stories, they are not reality, they are not absolute truth.
This is how all wars start. Two people, two nations have their own version of reality and they can't agree, to the point that any damage is justifiable in proving that 1 + 1 = 3.
Why not work on a different equation? One where 1 x 1 = 1. Now that would be a world I would want to live in.