Perhaps you were bitter enemies in a past life, or warriors on opposite sides of a battle. Somehow your connection was adversarial, and in this life you'll both sense the fact that you're fundamentally at odds. This feeling could deepen as your relationship progresses, so if you end up being together long-term, don't be surprised if you both become more and more frustrated with the fact that you can't seem to get your needs met, much less understand your partner's needs.
You may have very different ideas of the meaning of personal and professional success and how to pursue that success. If you try to work together on a long-term project -- such as, say, the relationship itself, or a business endeavor -- you'll find that you butt heads repeatedly about methods and means, unless you clearly define your separate duties and responsibilities. You need different things romantically in order to feel stable in your relationship, and this can cause some problems between you unless you can both work hard to communicate and compromise. You can resolve this difficult karma within this lifetime, after all. If you fall in love and want to build something lasting together, you'll have to tune in to each other, accept your partner despite their differences, meet their needs as best you can, even when they make no sense to you, and generally work to help each other overcome your insecurities and feel solid within the affair.