Bittersweet

Forrest Gump was right: life is like a box of chocolates, you never know what you're gonna get. Sometimes its a sweet surprise, and sometimes it is just plain nasty.
Life is like a box of chocolates, and life is also bittersweet. It is a combination of both the pain and beautiful, the sweet and bitter experiences of life that grow us up as people and change us in ways we never dreamed possible.

Shauna Niequist sums it up so perfectly: "It is a combination of both the hard and beautiful moments of life. Bittersweet is the idea that in all things there is both something broken and something beautiful, that there is a moment of lightness on even the darkest of nights, a shadow of hope in every heartbreak, and that rejoicing is no less rich even when it contains a splinter of sadness. It's the practice of believing that we really do need both the bitter and the sweet, and that a life of nothing but sweetness rots both your teeth and your soul. Bitter is what makes us strong, what forces us to push through, what helps us earn the lines on our faces and the calluses on our hands. Sweet is nice enough, but bittersweet is beautiful, courageous, and gutsy."
I remember hearing a professor talk in class during grad school that some people go their life trying at all possible cost to avoid pain and suffering. That they spend so much energy avoiding the bitter, painful moments of life, they can end up missing out on some of the most amazingly, beautiful moments as well. At the time, that sounded crazy to me: "How can you go through life avoiding the icky?" But as I look back on my own life, I think to some extent I have tried to do that too in my own way.
I think I only wanted to learn from the sweet, good moments in life. Instead of allowing the difficult, bitter ones to do some deep-down soul work in my life. Whether people admit it or not, we all will experience pain, suffering, and difficulties. There's just no possible way to escape or avoid it, no matter how hard you try. It is a reality of the human condition. But if we allow it, the bitter, hard moments can be some of the most life-changing and transforming.
Don't let life make you hard or bitter, let the pain stretch you like a rubber band. See difficulties as a way to learn more about yourself. 
Life is a reckless, confusing, beautiful combination of both the bitter and the sweet moments. And it is in how we respond to those moments that can change us for better or worse.

What have been some of the most profound, life changing bittersweet moments in your own life? How have they changed and shaped you as a person?