It always comes up. The moment you mention that you went to graduate school for a degree in Library Science, someone will ask you, "How hard is it to put a book on a shelf?" That is when you flash your professional smile that says, "How clever you are," and reply, "You would be amazed."
Inside you want to pin the idiot to the nearest wall and shout at the top of your lungs, "I am a master of data systems and human-computer interaction. I can catalog anything from an onion to a dog's ear. I could catalog you! I wield unfathomable power. With a flip of my wrist I can hide your dissertation behind piles of old Field and Stream magazines. I can find data for your term paper that you never knew existed. My knowledge extends beyond mere categories. I cannot be confined to a single discipline. I am all-knowing and all-seeing. I bring order to chaos. I bring wisdom and culture to the masses. I preserve every aspect of human knowledge. And I will kick the crap out of anyone who says otherwise!"