In life, no matter how much good there is, you can always find something bad if you look for it. You can find some fault, some weakness, something that you don´t understand or like. You can either develop an eye for the good, or you can develop a critical eye and always see the bad.
This is why marriages are in so much trouble today. A spouse or both spouses have developed a habit of being negative and only seeing the negative. They´ve become too critical and view everything through their critical eye.