There are many many reasons to like philosophy, but if I had to settle on just one, I would probably have to say that what I love about it is its inherent playful ability to turn the conventional wisdom of our time and what seems intuitively obvious into something downright bizarre and highly questionable. Needless to say, it does require a peculiar kind of personality to be comfortable with ambiguity and open questions, but isn't that exactly what it takes to gain any wisdom?
One of my favorite examples of a philosopher running wild with a simple idea (like that all our knowledge derives from experience) is David Hume's thoughts on the idea of the self.
Descartes once argued that if there is only one thing you can know with certainty it's your own existence. Taking Descartes' own idea of ideas, Hume demonstrated that you can't even be sure about that, as the following incredibly short and funny summary of Hume's view demonstrates:
Check out more of Hume's ridiculously awesome awesomeness.