I've been teaching some books about specific obsessions, and in order for my students to understand that I was not judging or maligning the authors for their obsessions, I made a bit of a joke about understanding obsession myself, about being obsessed. I mentioned my nine years in graduate school and detailed how I'd not only read and annotated all that Lord Byron had written, published or not published, but also had read and annotated the thirteen volumes of his letters that we have and had read and annotated the letters sent to him and had even started reading and annotating all that Byron himself had read . . . in chronological order.
(And that's not counting the bookcase or two full of literary scholarship on Lord Byron and English Romanticism and European history and heroism I also read and annotated.)
What started out as a joke became a little more serious: I do understand obsession.
I survived mine, but not everyone does.