Update: Spent most of the day, and up until about 10:PM last night with my dad and family. We talked, watched a movie ("World's Fastest Indian"), and had dinner.
At some point during the night, my dad started referring to me as his best friend from childhood - Mike - who passed away several years ago. I went along with it, and we talked about our escapades as kids, and the petty vandalism we got up to.
Mike was like my second dad for my whole life. He was a wonderful man. And I was both honored to be serving as "Mike" for my dad, and saddened by it.
Last night, when he was talking to "Mike", his eyes lit up in a way I haven't seen for a long, long time. The two of them had the closest bond, going all the way back to the day they met in preschool, when Mike pushed my Dad into the fish pond.
Giving my dad that gift - a conversation with his best friend - was an honor.
Dementia, man. The sufferer may not know it is happening and is having the time of their life... but those around them see the reality of the situation.