[Solfy]

When my grandmother started to complain that my grandfather was losing it, we thought it was just more of her usual poking at her husband. He seemed normal to us.
After she passed and my aunt moved in with him (it was one of grandma's dying requests because she knew what was up), we learned that grandma wasn't just picking. Sure he had really good days where he seemed completely normal, but there were others where he'd forget what red lights meant while driving, or who my cousin was. In the beginning he could have nailed that assessment if you caught him on a good day.