Anterograde amnesiac with selective memory???
Aside from the anterograde amnesia, I think Lenny may be blocking out things that he DOES remember but doesn't WANT to remember too...selective memory. I think that's where Sammy and Sammy's wife come in to the picture. He knowingly created a fictitious couple to keep himself from thinking of his wife's death until he actually believed they were real. That would keep him from remembering overdosing and killing his own wife.
I don't know, just something more to ponder. 😊
"Ain't life grand!"