Lois could hear the familiar Bach prelude wafting upstairs from the piano and she was pleased that I was playing, since I usually wait until she’s out with Jack to do so. Jack has a tendency to howl or try to climb in my lap, though whether that is a complaint or a desire to perform a duet, we don’t know. Our daughter Susannah was in for a visit, and Jack wasn’t howling, probably distracted. But, as Lois listened, she noticed the prelude sounded a bit halting, with a few mistakes. She paused, worried in that moment, for the first time, that Alzheimer’s might be showing itself this way, and came downstairs to look in on me. She was relieved to discover it wasn’t me at all – it was Susannah, the flutist in the family.