"A good deal is said these days about being oneself. It is supposed to be healthy to be oneself. While it is a little hard for me to understand how one could be anything else, I suppose what is meant is that one should not strive to become anything other than what he is. This strikes me as a very dull way of living; in fact, I would be inclined to argue that all of us would be better off if we set out to be something other than what we are. Well, I’m not so sure we would all be better off - perhaps it would be more accurate to say life would be a lot more interesting.”
More on George Kelly, from George Boeree's Personality Theories website.