Something I love is finding out that I'm wrong about the way something in the world works.
Whether due to my own misunderstanding or simply being given incorrect facts, I sometimes find myself learning that previously-held beliefs are incorrect. A fantastic example of this comes from a chemistry teacher I had in school, who cheerfully informed the class of a secret: glass was not a solid, but a high-viscosity liquid. She explained how over time glass actually oozes down with gravity, and cited the windowpanes in older buildings as proof of this that we ourselves could examine if we so chose. This tidbit of information was one that I carried with me for years until I found out that it simply wasn't true -- it's an amorphous solid.
Of course, the technicalities of whether glass is in this or that state of matter is fairly trivial in terms of real-world relevance for the majority of the human species, but it serves as a springboard for more exciting things. The entire history of scientific advancement has been a battle against prior misapprehension -- the Ptolemaic Model of the Universe, the Bohr atom, &c.
Perhaps equally important for the individual is that the sudden shift in perspective allows one to, if only for a moment, experience an acute sense of one's own fallibility in an arena where one can't actually get hurt. If I were to ever go into teaching, the first homework assignment of the year would be for students to go online and discover a piece of information that they had been fundamentally wrong about. You can do this now, just go to Wikipedia's list of common misconceptions.
Perhaps the old cliché says it best: you learn more from your mistakes – or your misconceptions – than your successes.
"I really can't do a good job, any job, of explaining magnetic force in terms of something else you're more familiar with, because I don't understand it in terms of anything else that you're more familiar with." - Richard Feynman