Through the natural support and affection that you'd give to anyone with whom you were intimately involved, you help your partner map out their best future path. Your love gives them the strength they need to move forward in life, and your relationship serves as a solid base from which they're able to move outward into the world. Your love actually helps them to access parts of themselves that they may not even know exist.
You help them figure out what's most important to them in terms of their values, their expectations in love and their future path. Your natural courage helps them to feel brave. Your lover might even feel as if you were meant to come into their life, and you may well have been. Just make sure that you're getting more out of the relationship than just this person's gratitude -- which you already receive in spades. They love you for the effect you have on them, and that's a powerful bond between two people. You probably love feeling so wise and needed, because this relationship really puts a focus on all your best qualities. You both communicate openly about your dreams and ideals, and helping each other turn those dreams into reality is a driving focus for you and a big part of your bond.