I love the pursuit. I get a thrill from tracking down the reference in the reference. If this means that reading a book requires me to read six books, then so be it. I come out the other end not only having read the book, but having constructed my own understanding of it by getting closer to the sources the author originally used; invariably I form a different opinion, sometimes one that makes we question how the author drew these conclusions as my own thinking are different. This is when you see how, like journalists, even authors of academic texts, of necessity, have to be selective. This is particularly the case with history where interpretation of the past is exactly that; a turning over, sifting and retelling of the events.
The drawback of an obsessive nature is when you feel a compulsion to see every episode of Game of Thrones, and when you're not watching the series you're reading up on the cast and crew in IMDB.