Yes, Wayne himself could have another lucid period and figure it out all by himself. I'm kind of thinking the last images of him disappearing in the foliage in Vietnam signal he's not really every coming back - but I hope not. I want him to have periods of being oriented and able to enjoy his renewed friendship with Roland...
FYI I believe I remember a brief scene in 1990 where Wayne is holding Amelia's finished book, in pre-published format, and remarks that it is good. This lead me to believe he had read all of the book but doesn't remember he has. So in 2015 he keeps saying things like I wish I had read this before and constantly uses it as a reference book for clues. (good writing IMO, adds drama, confusion, suggests additional tension between he and Amelia...)
And I agree, I think he would have made a note to himself so he wouldn't forget the significance of the address. Must have left it at home. LOL In the car he was so rattled he didn't even remember he had the address in his pocket, much less its importance.