Joe has early stage dementia, I've seen it before.
I just watched Joe Biden give an interview with Chris Wallace. First Chris congratulated Joe on his big victory, and made small talk. But at the end of the interview he confronted Joe on some gaffs and missteps or outright lies, however you look at them. I have to admit, Joe did a pretty good job explaining them all away, after basically admitting he goofed a few times, but at the end of the interview said, "Thank's Chuck"!
No joke. I could not stop laughing for about 3 minutes.
Joe was a gaffe machine when he was younger, now that he is getting older he is off the charts.