To a narcissist, the truth is not a finite entity. The truth is simply whatever they say it is at the time that they are saying it. This is so different to how most people are wired that it can be very hard to understand. Narcissists live a completely false version of reality every single day, as a defence against meeting and feeling their own shame and feelings of inadequacy, and lie to themselves and others about who they are constantly. That’s what their
false persona is all about.
When a narcissist tells their version of the truth, they seem to believe it 100% - and that is because they often genuinely do, for the duration of the sentence, at least. They can take your hands in theirs and look deeply into your eyes, as they wriggle out of whatever it is that you have expressed concern about. It’s extremely easy to be taken in, particularly when the narcissist plays the victim.
A narcissist’s lies can seem utterly convincing to those in positions of power, and this can be particularly difficult if you work with one, or are divorcing one (when judges may easily be taken in).