I've seen in parents/in-laws the effects of dementia and old age mental decline. I can't bring myself to mock whatever Joe's is (probably the former). Dementia doesn't follow a timeline, linear or otherwise. Joe might crash and burn in a few months, and he might live in an ALF or SNF for another 5 or 10 years.
But sympathize? No! What he has done to the US and to the world - as Senator, VP, and POTUS - precludes that.
So Joe will speechify tonight. Will he be honest about his declined and declining mental state? I doubt it, as the 25th amendment would be in prospect. Will he wax nostalgic? Maybe, some. Will he tout Kammie? Probably, some. Will he blast Trump? Oh Hell, yeah! Joe's general Trump-Hatred and bitterness over dropping out guarantee that. Will he lash out at Dem leaders and donors who pushed him? Very possibly. Joe's a mean old guy and will be to his very end. It's what Joe is.