Angelica, I thought the same thing about my xh--brain tumor. It's the depression that creates such havoc w/their memories and other behaviors.
Will they forget they are married to the ow? No. But they do forget the general, routine things that we know that they should remember. Eventually, as they come out of the fog of depression, they do remember some things, but not all of what they've done.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
