You two likely find your communication to be challenging, your interactions tricky at best. You both came to the relationship with the best of intentions, but you probably find yourself irritating your lover or offending their sensibilities. Neither of you is directly at fault for the flare-ups that are almost unavoidable between you; the problem lies more in a very basic difference in natures or temperaments.
You are highly attached to your own, individual character and your own view of the world. Whenever you two try to communicate, you've found that your experiences of life in general are at odds with your partner's -- and the likelihood is high that both of you feel threatened by these differences. The problem is that you, especially, attach your ego directly to your opinions, which means you're unable to step outside your own point of view to see your partner's side of the argument. In a romantic relationship, this kind of challenging interaction can breed mistrust, and trust is essential to a healthy connection. Of course, if you're both hardy, adventurous sorts, you could look at this as a personal challenge: You both stand to learn a lot from each other, as you're required to let go of your own egos and strive to put yourselves in the other's shoes. But without a concerted effort to expand your own mental horizons, it's much more likely that you could just end up feeling challenged and misunderstood.