Most of these people I think somehow manage to fail some mental check on internal dialog. Of course our internal dialogs are like “do iiiit!”, but most of us recognize that as wrong and ignore it. I think these guys just go “Oh, lord I’ve been waiting to hear from you again! Oh, I should just do anything I want!? COOL!”
I think there are some genuine delusionals in the mix for sure. But yeah, I’d guess that it’s mostly psychopathic liars.