That did happen to me. Especially because after the end of book 4, the main story doesn’t continue until book 6. Book 5 is a whole new cast or characters, new continent, etc but it’s so worth it! Book 5 is my favorite in the series so far.
Between each book I usually take a 2 month break. Only time I didn’t was between books 5&6. About 3/4 of the way through book 6 I felt the burnout and then it took a couple of weeks to finish that last 25%.
Like you said in your weekly update probably not because they mean something to me. All of the books I’ve unhauled recently were books I bought that I either didn’t like or lost interest in. I think I’ve unhauled around 20 or so in the last few months.