Because I'm procrastinating on stuff I feel almost well enough to do, ( a meme not only copied from several of my friends, but based on guesswork about my friends )
The problem isn't that I don't own obscure works, nor that I have exactly the same tastes as all my friends; it's that I and most of my friends have such broad tastes and interests, and I've got such a broad assortment of friends, that even the obscure stuff overlaps. Lots of answers come to mind if the questions are changed to "... that very few people on your friends list have".