He blurted out weird stuff even before he had dementia - I think he must have suffered brain damage when he was young.
https://mobile.twitter.com/rhowardbrowne/status/1460706716891455491
He had two brain surgeries for an aneurysm in an area of the brain that affects impulse control. I have a friend who is a vascular surgeon, who said that only 5 to 10 percent of people who have that surgery emerge completely unscathed. Biden is not one of them.
Pathological liars say whatever it is they feel like saying at the time. It appears that Biden has been a pathological liar his entire life