We often find ourselves thinking about how things could be better. If we just had that one extra thing, we can be happy. For example, imagine that your chemistry TA is a real jerk. He is always losing your papers and making it difficult for you to get a decent grade in the class. You think to yourself "If only I had a better TA," considering you're having to do more work than what's supposed to be expected of you. While I know that this example would be extremely frustrating, in reflection it's easy to see that the person experiencing this is learning so much more than just chemistry. This student has the opportunity to learn how to deal with difficult people better than those not in their situation. We become so accustomed to only looking at the negative side of things without realizing that although we're going through hard times, we're learning how to make similar experiences easier for us in the future.
The same thing goes for friendships as well as relationships. Sometimes the people we come to love end up hurting us, whether that be through a nasty break up or spreading rumors. No matter the cause of your distress, it caused you to know a little bit more about what you want in a companionship and how to avoid being wounded again. I was once told that "not everyone you lose is a loss." Knowing what I do now, I finally understand that God places some people in our lives for seasons. These people aren't meant to stay forever, but to teach us a lesson and move on. I believe that every time someone leaves a relationship, the other person gains a new piece of themselves. Rather than having a vindictive attitude towards those that hurt us, we should want to learn from that pain and use the knowledge gained in future judgments.
In my opinion, looking at the bright side of things is a necessary part of life. How else are we supposed to justify our feelings? Is it intended for us to indefinitely be searching for what we think is missing in our lives? There's no way. Wishing for solutions to our problems that we don't even know would actually work is pointless, and unless we start accepting things for what they are we will never learn how to grow as individuals.