To Change or Not to Change?

I am struggling with the concept of change.  There are many kinds of change and I like to think of myself as a master of many.  To begin with, I move with my husband and two children every 3 years or so.  This in itself necessitates many changes: country, city, house, school, friends, stores, cars, and a general way of life.  I like to think that I deal with these kinds of change quite well.  But recently I have become aware that despite all these external changes that I have learned to conquer over the years, there is one change I am loathe to consider: changing myself.

It has been recently and frequently drawn to my attention, in many different ways, that there are parts of me that are not, perhaps, ideal.  I have been adament about not changing anything about myself simply because someone else tells me to.  I do not believe I should change myself to please someone else. In fact, this is one of my fundamental core beliefs: if you don't like me for who I am then tough shit.  I also fundamentally do not believe that what I do is a reflection of who I am.  I don't believe that being a poor housekeeper does not make me a bad person any more than working a 16-hour a day job makes one a good person.  As the joke goes: sitting in a church every week doesn't make a person a Christian any more than sitting in a garage makes a person a car.

But what if I'm wrong?  What if changing some parts of myself and my behaviour would actually benefit me in the long run?  What if these other people are right and they just see that I can be a better - or at least more productive - person than I currently am?

So I am torn.  Lately I have lost enough self-confidence to start thinking that maybe I should work on improving myself.  But where is the line between changing for someone else and changing to improve yourself (at someone else's suggestion)?