Are we looking the right way?

Recently a friend of mine came to talk to me. She was really angry that her boyfriend turned out to be nothing like she expected him to be. It wasn't that he cheated on her, not that he acted behind her back, and certainly not because he didn't spend time with her. Still, "he changed a lot" was what she mentioned. Looking back, it didn't seem like anything changed, rather perhaps her expectation on him grew a little bit too fast. (For example, he usually carries her books; but now is accused of being careless "couldn't care less if it fell on the ground", he used to send her home, but she doesn't like the way he drives so slow and so on).

Now, I don't think there is anything wrong with them, certainly I don't think we should be blaming my friend. I feel it's just a mismatch of personalities.

How so?

What I advised her was to take some time off and really reflect on what she wanted. If that is what she wanted, she should continue. If it wasn't then she shouldn't continue. What I feel is not the right thing to do is impose on others what you want the person to be, because it is easy for a person to shrink up and withdraw when he or she is nagged (then they will resist change). I felt it was better for her to resolve the important matter - which is done by looking at oneself first.

After all, we all make mistakes. And most of our mistakes are made because in our impulse we do something we don't really need to (instead usually its something we "want"). We then justify it so that it looks like we need it. How many times has this been done, when it comes to everyday life? We like a person, so we go out with them, then finally when things don't go the right way, we justify our choice, "no I am quite sure I can change the person to xxx and so on". We become defensive when arguing over what we did was correct. Is this the right thing to do?

My friend believes that the guy should change for the better, and leave his bad habits behind. I don't blame her - many people feel that way too, regardless of gender, race, nationality, etc. This human thinking flaw knows no boundaries. So now we have two contrasting opinions on either side - what do you believe is the better one?

(Obviously I am explaining from my side of things, so the post will look biased, but it's best that one ponders the issue through).