When Biden was younger did he stutter? I didn't think so. Is that a thing that starts in older age?

When I listen to the confusions in his speech they seem more than just avoiding word. He will say that HE is the vice president before then correcting himself. This is not stuttering. But it is also not complete loss of understanding either. It is a mental gap.

My personal guess is that he IS far less sharp than he was before, but that he still knows basically what is going on around him, and he likely is still calling the shots regarding which paths to take and which people to listen to.

BUT I bet it is hard for him to focus for long periods on the technical details of complex decisions with multiple interacting factors. In my estimation, that is a loss for the nation. (Of course if I were to give high marks on this score they would go to Obama, then clinton/bush senior. Many other presidents for other reasons that health seemed ill suited to deep reasoning.)