You have a deeply emotional bond, but it could be an elusive one -- and, worse, it could obscure your individuality in the face of trying to hold onto your bond as a couple. This doesn't happen because of any sort of deliberate manipulation on your part or your partner's, of course; it's just a natural quality of your relationship. You can only work through it if you recognize that it's there.
This person has an elusive quality to their personality that draws you in, like a mystery just begging to be solved. In this case, solving the mystery that they present might not be the best use of your time and energy. While it might feel romantic for you to place all your attention on them, trying to figure out who they are and what makes them tick, it isn't the best thing for either of you as individuals, because you each need to cultivate your own life, your own ideas and individuality. This relationship may or may not last, but your individuality does, or at least it should. Your partner should help to steer you away from becoming obsessed with them, and to learn that being yourself, rather than being consumed by someone else, is really your best course in life.