Well it certainly can be! There's much to be said for consistency as well though and I think fickleness is born out of dissatisfaction with what one has and a curiosity that perhaps something better is out there, so there is also an element of immaturity and inexperience.
Men and women are both fickle minded especially the immature ones. Self-discipline can help control the fickle mindedness of a person. However, there is a difference between "I change my mind" from "I change my decision".