Authors/readers, in a series. what do you feel is the right amount of info-dumping to get the reader up to speed on "the story so far"? I'm sometimes frustrated with authors, where after the 7th+ book in a series, they attempt to get reader up to speed on every piece of backstory (repetitive). After 7+ books, can't an author expect that the reader is likely invested enough to know what's going on? Are there readers that will start a series 7 books in?