Why is grief more powerful than happiness?

Somehow today I kept thinking about grief and happiness.
The most striking and cruel part is the way happiness is in a moment. It's attached to a particular place and time. It can't be transported to another time and space. Though sometimes, you may be taken to past, thinking about the good times. But in the end, you are left wondering and longing-to live once more in that moment.
And grief! It travels with time. It can fill your space, time and life too. It is not transitory in the least. You fight it or accept it. In either case, it fills your life.

In happiness we resist change. Life is perfect at the moment. But grief has the power of shaping our destiny. Why are we the way we are? On reflection, the only answer that comes to my mind is that for good or for bad, my life and probably everyone else’s too is shaped by those moments when we were not feeling at the top of the world but when tears were rolling down our cheeks, when prayers were on our lips and when we were desperately searching our souls for some hope.

Even after so much said and preached, I know the next time I am surrounded by dark clouds, it would take me a long time to see the silver lining. But, I hope to have the strength to see it through everytime