Changing your mind. That's part of being on the Enlightenment Train (don't need no ticket, you just get on board). It's built into the scientific method, test your hypothesis, see what happens. So changing your mind, about events, people, is a fundatmental principle. There's shifting perceptions, shifting loyalties. What do we have to hold on to, what do we cling to, what do we resolve not change our minds about?
Everytime we "make up our mind," we close a door. Living in a world of closed doors may allow us to feel more secure, but doesn't it also isolate us, cut us off from new experiences, new ideas, new perspectives, other people, etc? Open door, open mind.