This is about the option or right to change one's mind. This can get you out of a stuck situation (see SmartPeopleStuckWithBadIdeas) which requires self-discipline, but can also be seen as narcissistic (when you change your mind just to avoid the consequences of your prior actions. In short, exercising this right his has the following consequences:
Pro:
Some people abuse the OptionToChangeMyMind by doing it too frequently, these people are either unreliable, or lack the judgement in knowing where to draw a line in the sand.
Contrast this with the mentality of people who defended to the bitter end an untenable position, or others who never aired their privately held views so they do not have to be accused of changing their stories.
I heard of someone, who used the OptionToChangeMyMind in a very problematic way: He more or less obviously changed his mind, but claimed not to. I presume to avoid admitting, that he was wrong.
How to use this right?
See also RightToChangeMyMind which caused this OffSpin?.