You could have a hard time finding common ground. This could be a subtle sensation or a powerful one, but on some level, you both recognize that you speak a different language. You likely feel frustrated when you're together, as if you just don't communicate in the same way or focus on the same things in life -- and for the most part, you're right.
You are different enough that your values and beliefs may not even be complementary. This can present problems when, for example, two opinionated types keep butting heads, each trying to convince the other that theirs is the right way to look at things. Qualities like stubbornness are brought to the fore in this relationship. But it can be just as problematic when one or both is the type to maintain harmony at all costs, as hurt feelings are never brought to light and resolved. You each may feel as if you're hitting a brick wall when trying to communicate, but this could actually be a very positive experience. If you can both learn to step outside yourselves and see things from the other's point of view, you can learn a lot about life, love and communication, not to mention about yourselves and the ways you look at the world. You can learn go view each other without judgment. Your souls stand to do a lot of expansion and growth through the course of this relationship; your deepest beliefs are challenged here.