Because the multitude of skills required to navigate through the long and tumultuous journey of life are acquired only through experience that builds into wisdom. You can have everything else going for you, but if one or both of you are not mature, you ll either fall into destructive patterns, sink into depression, or drift apart. The most overlooked factor in successful relationships is maturity. Those who expect perfection are always disappointed. Those who try to be perfect are always failures.
Relationships are about trying.