Lost, lost, lost

This may be a theme for a bit.
Overall Bob still sleeps well at night. He can even get up and walk down the hall to the toilet. However, returning to bed has become enough of an ordeal that I am fully awakened nightly.
He generally makes it back to the bedroom, but he has a tendency to make a right turn which sends him to my side of the bed (one time he plopped down on my sleeping form!!! that's one reason why I make sure I wake up) but more often he can sit on (his side of) the bed and then begins a fumbling mess until he manages to get under the covers without shoes. Almost always he needs my assistance.
A couple of nights ago I was aware that he'd not returned to the bed in an expected amount of time (a week or so ago I had found him down in the kitchen wandering about; this time I looked into the bathroom, didn't see him, went in search, no luck. I returned to the bathroom to look again and glanced into the connected tub room: he was standing in the tub.
Unthinking I asked, "What are you doing in there?"
"Where? Where am I?"