The History of Middle-earth is a 12-volume series of books that collect and analyse material relating to the fiction of J. R. R. Tolkien, produced by his son Christopher Tolkien. They are extremely detailed, to the point of documenting scraps of paper that have been erased multiple times with hundreds of footnotes. In analysing this material in such detail, Christopher Tolkien seems to have been as obsessed with documenting the history of the writing of the Middle-earth stories as his father was with documenting the fictional history of Middle-earth itself. In these cases, it would seem that obsession is not necessarily a bad thing.
