What incites a person's ability to change and does the reason prompting change really matter?
Unequivocally, every day is an opportunity to alter the course of one's existence and the only way to do so is to be prepared to change. In order to grow and evolve within ourselves it's actually necessary to create change or we become stagnant, closed-minded, and ultimately, unhappy. I also strongly believe that the only way to elicit change is on our own. Granted, we all need help to sustain any truly profound reversals of behavior within us - we all need reminders and repetition to help make anything "habit". But it is that inner desire, that voice inside us that decides for us how we will become our future.
Every day is a series of choices we make; some obvious and conscious, others mindless and "knee-jerk"...it's those "knee-jerk" responses and choices we make that usually get us into a fix, and it is those that are most difficult to change. One has to first SEE that it is how we are habitually responding, DECIDE that the outcome of such is "good" or "bad" for our current situation or relationship, and then MOVE to change those reactions to improve our lot in life.
Self analysis is never easy, but it is one of the most rewarding experiences one can have because it not only affects our own scope of existence, but in most instances has far reaching results on those with whom we come into contact on a day-to-day basis. Our most significant choice in this life is whether we want to exhibit humanity by instituting changes within ourselves, or to remain in a self absorbed bubble believing that it is not necessary to change since "we're not hurting anybody."
As for the antecedent to change having any significance? The only weight it carries is its import in that person's journey to change. Some things are far more of an impetus to evolving than others (witness the person who gives up smoking after 20 years when they see a loved one die of lung cancer...or the man who finally sees where he lacked as a husband or father only after his wife of many years leaves him and he then becomes the best of who he is able to be to his next spouse). Each one of us has different values and mores in our lives that carry different levels of significance to us...it is those that are of the highest import to our core being that usually prompt long term change, but what those things are really only matters to the one in whom it elicits the change.