One of the few benefits of getting older is that you can actually reread some of the books/series that you enjoyed 40 or 50 years ago and not remember exactly how it ended

That said, I will read the first book in a series (first book by an author) when possible and if I really enjoy it ration out the rest, reading a few non series books or another type of book in between. Then on those bad days at work when I want to pillage and kill, I have a truly satisfying treat.
And of course when you have read one of your favorite authors twice there is nothing like the little thrill you get by coming across one of their books you have not yet read
Helen