The Frugal Wizard’s Handbook For Surviving Medieval England, by Brandon Sanderson

Who will be planning to read the e-book, the print version, or listen to the audiobook?

I haven't read the book, but two of the elements that you mentioned; personal "dimensions" or realities, and amnesia, remind be of Roger Zelasny's Amber series, where the main protagonist wakes up in a hospital with no memories and has to work out who he is and what role he plays in the events unfolding around him. It's an interesting journey from the prosaic to the fantastic.