Your partner naturally takes on the role of guide or mentor in this relationship -- being, perhaps, older or more financially stable, or having had more education or general life experience. This should be a comfortable dynamic for both of you. You have a lot to learn from your lover, and you actually want to learn these lessons.
Your relationship is grounded in practicality. You've both known, almost from the start, what your limitations are as a couple -- meaning, what works and what doesn't. You both understand and accept the type of communication style you share, and don't expect dramatic declarations of devotion or swells of emotion. This is because you both understand that the bond between you runs deep and true, and doesn't need qualification or even reiteration. Similarly, you both also know and respect the physical connection between you, and even if you're not exactly in sync sexually, you don't push one another to be a different kind of lover than the one that you are. Precisely because you don't push one another to be someone you're not, you're able to grow as individuals in a natural way through the course of the relationship, regardless of how long it continues to last. After all, you both have something to offer the other -- your lover can offer that life experience and knowledge that you lack, and you can offer them a sense of freshness and vitality that keeps the relationship new and exciting.