I always had my doubts since my dad lost his motor skills (ability to walk/talk/write), had paranoia, and also would not sleep at all. Though his short
and long term memory were in tact. I would see him about every 3 months
and he always recognized me, my kids, my husband, etc. He also never forgot my mom - his caregiver. He would tell stories both current and from the past. He did not repeat things.