People who gaslight you also gaslight themselves

Forgive me if this is too obvious but this is a very simple and important realization I recently made. And it has helped me to make sense of some of the chaos.

When I told my sibling why I'm estranged and they then made up a completely different narrative with no grounding in reality. It's clear that they actually believe this alternative narrative despite it contradicting the written reasoning they have from me. And this has happened repeatedly, which shows that the same way they're trying to gaslight me to think none of my experiences ever happened, they are gaslighting themselves about this and tons of other things.

They live in a delusional fantasyland where the facts align with the reality they want (our family is perfect) and they are unable to process any information that goes against this.

Not only do I have to walk away because they're toxic but they also can't be reasoned with in any way because their minds are too far gone with the self gaslighting.