Knowledge
To me, a thirst for knowledge means more than just acquiring new facts and information. It is a lifelong pursuit to become a better human being, by correctly understanding oneself and others.
For me ignorance is definitely not bliss. When one first discovers philosophy one learns that it means, quite literally, the love of wisdom. It is the search for knowledge that allows us to begin to understand the world and our place in it. Doing philosophy is being able to clearly articulate what it is that we believe and what we believe in.
Know thyself! —Oracle at Delphi