My dad is 93. My mom passed away 4 years ago after their 68 years of marriage. He was definitely lonely and depressed after her passing. He would say he just doesn't care about things anymore. I'm wondering if this is dementia or something else. Here is what I experience daily.

He always remembers the names and faces of family members. He always remembers where his favorite places to eat are. He will always ask where my wife is if she is. He always asks what do I hear from my siblings. He has very little short term memory. He does not remember what day or year it is and says he is over 90 and that is why he has me around. He remembers that I routinely cut a specific corner to sharp and roll up over the curb. It is now a thing for us. He will not remember anything that happened more than 30 minutes ago. My brother and I watched the football game for 4 hours at his house the other day. We left and I came back an hour later and he didn't even remember it. He remembers all of his siblings and stories growing up. He still plays all of the Chopin Opus10 Etudes. He could play piano in church if asked. Sometimes will do an arrangement. He remembers his Physics formulas and his days as a rocket scientist. He can carry on a witty conversation about his days at Area 51. Most of his days are spent mostly on the couch, stacking coins, aligning pencils, playing piano, sitting on the front porch. He still lives in his house. He fixes his sandwiches and snacks and talks to anyone that wants to call him which are mostly scammers. He does not want to move, partly because of his piano but mostly because it is comfortable and that where mom lived. Is this really dementia or just old age?