Pluto

Why do people get emotional about such an arbitrary thing as the classification of a heavenly body? Because you have a nostalgic childhood memory of learning 9 planets? What a stupid reason, the model of the solar system has changed and still is. You know, Pluto's orbit is actually littered with objects almost the size of Pluto itself? More complex terms are needed to describe what we know is true and to be opposed to this is to demonstrate your own ignorance.

Because pigeonholing is something profoundly anchored in the American civilisation, and the difficulty to pigeonhole Pluto, or worse, recategorise it, is profoundly disturbing.