Your romantic feelings for each other could be suffering under this influence, because you're always on a different plane, mentally and emotionally. Your partner is more freeform in their thinking than you are, which could be coming across as an irritation to you, since you're more grounded in your thinking. These very different ways of looking at the world and any given situation in it inevitably leads to misunderstandings between you, and even arguments.
There is a constant struggle on both your parts -- you are always trying to get your partner to focus and communicate in a clear, logical, straightforward way, and they are resisting, fighting to remain the person that they are. You probably misread their romantic cues, as well, or just don't trust them. It's not that they are untruthful, either. They just have a different way of being in a relationship and of expressing themselves that is unrecognizable to you. When one of you is trying to be loving or sensual or romantic, the other might be holding back just a bit, wondering somewhere in the back of their mind, Does this person really like me, or is it all an act? This kind of thinking might actually be a projection of your own feelings! You should both try to remember that you're simply different people, but that doesn't mean your partner is dishonest or flaky or anything else of the sort. You have to work to understand each other.