Gail Godwin said this quote

There are two kinds of people. One kind, you can just tell by looking at them at what point they congealed into their final selves. It might be a very nice self, but you know you can expect no more suprises from it. Whereas, the other kind keep moving, changing... They are fluid. They keep moving forward and making new trysts with life, and the motion of it keeps them young. In my opinion, they are the only people who are still alive. You must be constantly on your guard against congealing.