Expect to have a hard time with each other when it comes to growing as individuals within the relationship. You are on a highly emotional path toward self-knowledge during this relationship; you're doing a lot of hard work and personal transformation, and this personal struggle invariably ends up pulling your partner in, even if they don't want to be. A further part of the problem is that you have such different ways of meeting issues and translating perceptions -- you're polarized between logic (your partner) and emotion (you), and you have a hard time even speaking the same language, much less understanding where the other is coming from.
A third part of the problem is your tendency to project your subconscious need for change onto your lover. While this should be a personal process, one that would go on whether you were romantically involved with them or not, instead, you start to try to change yourself through them somehow. You might focus overmuch on the relationship, ferreting out where your connection needs change, and put too much energy into that and not enough into yourself. It could be that the relationship is just fine, after all -- and it's you, or your partner, that needs the work! You two might have a hard time getting along as a result, especially if you start putting each other on the spot about your beliefs and trying to force a defense of the qualities that make you who you are.