Berty is just a RW ranting Karen, who doesn't like being pressed with inconveniences like facts, or reality.
Perhaps the echo chambers that are FaceAche and Mumsnet would be more to his taste (y)
He's convinced himself that it is the truth.
That's how they reconcile it in their minds.
I've seen his type before .
What sets them apart is just how easily and quickly they can convince themselves that black is white, and how absolutely they can believe it.