I've never heard of these books, but after a quick Google search I realize why. They weren't insanely popular and they came out in the 70's.
Plot resolutions ending with amnesia and 'all just a dream' trope is just lazy writing. Well, the amnesia can be done well, but it usually isn't. Good luck on your journey back into a book series you loved, I'm sure you'll come out if feeling very differently than you did going into it again.
?i used to like Rick Riordan books and when I revisit them today I realize how immature they are