That being said, I don't think fantasy in "real" relationships after a certain point (like the "honeymoon phase") is always healthy, because it keeps blinders on us and we continue to block out the negative aspects of someone or aren't see something for what it really is. Learning to adopt certain untruths can keep one in an unhealthy, even abusive situation. Of course there are traits we don't like about every one, but I don't think we fantasize that they aren't there in healthy relationships, I think we learn to accept those traits.

This^ isn't at all what I've said.

b) we both change in ways that complement each other and the relationship grows/ changes in a good way

This^ reflects my point. The changes we make are conscious and freely chosen.