In fact many relationships sour for the same reason. Rather than focus on the positive, people focus on the negative. It causes unnecessary suffering. Learn to focus on the goodness amidst the pain, and you'll discover the maximum goodness that life can possibly offer. The greater pain we experience on the way toward a goal, the greater we enjoy the success of reaching it.
Human beings can actually derive pleasure from overcoming pain.
People will swim in ice-water or walk over hot coals just to conquer the pain of doing so. Overcoming pain gives us a sense of our own free will, and how much we can shape our lives. Learning wisdom is a good example of the value of struggling. Wisdom is the most valuable tool for living a meaningful life. Learning wisdom means taking the time to research an idea, working to understand it, integrating it, and practicing it over and over again.