I think it is just human nature to resist change when things are going well, and yes, if you attribute what you have always done as a big reason for your success, it is understandable why you would resist the uncertainty of change. With that being said, anybody can change, all you need is to have the right amount of leverage. Find the leverage you need and you can get anybody to stand face-to-face with the unhelpful beliefs that are the cause of their more negative behavioral traits. The thing though is that nobody likes to feel as though they are being judged, so one would need to make sure their approach is devoid of judgement or the attempt will more than likely fail.
Just my 2 cents for the day...