You may not notice until well into the relationship, but your most idealistic beliefs are incompatible in a subtle way. You both seek personal growth in your own ways, and after a while it becomes clear that you just don't understand each other's methods. Your partner is naturally more intellectual about it -- they actively seek new ideas that they can apply to themselves and their own experiences, and they probably read a lot, talk to different people and so on to actively shape their ways of thinking and growing.
You take a more passive and intuitive route than that. You're more apt to feel your way along, relying on your subtler senses to guide you along your path. Needless to say, these two methods of achieving the same thing are in conflict with each other unless you're both able to respect your differences. You could waste a lot of time arguing over it, asking each other, Why can't you be more like me? The answer is, because you're just not that similar in this one area! If either of you is to achieve personal growth during the course of this relationship, you have to do it either by agreeing to disagree on your methods, or by doing things your own way even under the pressure of your partner's disapproval.