Ripples: they carry within themselves just as much sorrow as joy. If you canceled them out, you would get the essence of being. Released in nature, water clears its own path. And in doing so, it rinses away and cleanses everything in its way. But, it does not hold things back; it lets them continue along their own course.
As you walk through your life, you are like water, equal parts sorrow and joy, in a state of being. But then, events pull you in close and your bag suddenly grows heavier. Your state is swung into one of sorrow or joy. And instead of letting it go, you continue collecting feelings along the way, and soon just one bag is no longer enough to hold them all.
What would it be like if you began acting like you were in a museum? You are allowed to look at the art, but you cannot take it with you. Look at each emotion you come across on your way, examine it carefully from every angle, and allow it to teach you something, but then move on without it. That way you will grow, but your bag will be light, as will be your step.