Although at first there might not seem to be any overt problems between you, over time, as your bond deepens, you both realize that there is a fundamental conflict in your needs for independence and for intimacy. These opposing but equally important needs probably aren't ever in sync between you two. You take on the role of the more independent partner, the one who requires freedom and alone time, possibly to the detriment of your lover's peace of mind and of the relationship itself.
They take on the role as the needy one, perhaps even the clingy one. These characterizations might not be entirely fair, but they take on weight and dimension through the course of the relationship. You are both likely to become bitter over the fact that your needs aren't being met. Your lover realizes they never feel completely supported or appreciated, and this is an irritating realization, to say the least. You, the partner who demands and requires freedom, may actually be the one who needs to make the most adjustment if this relationship is going to last. That freedom, guarded so diligently, may end up not being quite as important as togetherness in the relationship. If that's the case -- if you both decide to try to preserve the relationship -- much communication and compromise are needed.