There is a mountain range in Africa that is a watershed1. Rain that falls in one spot will flow to the Indian Ocean and rain that falls a few feet away will begin a far longer journey to the Atlantic Ocean. Imagine standing up there in a rainstorm and knowing that two mighty oceans will share the rain on your face?

Life is not that simple. The way we go is not decided by where our feet touch ground and, unlike the mountain rain, traveling through time and space does not necessarily take us anywhere. For us, every day is a watershed and consequences may be determined randomly by what we do and what we leave undone. We fortify2 our future with good intentions and elaborate plans, following carefully in the footsteps of tradition, pursuing our dreams; mostly we are good people pursuing good lives. Sometimes a smile at the right time can change a life; sometimes all the smiles on earth cannot lighten any part of a darkened soul. Still, we all go forward like the cold mountain rain, knowing there is no way back.

Would you dare to go back? It seems almost irresistible, to go back and rearrange the watershed, to chart3 your way forward again with advance knowledge of all the heartache and happiness ahead. Imagine you can carry the moon in a shoebox, like a secret adviser, to return to the moment when knowing what was in someone else's heart would have made the difference between fighting to the death or walking quietly away.

But the past is a riddle: it is more unpredictable than the future. It is the moody4 servant of our memory, unchangeable yet doomed to follow countless masters: every breath is an echo of the past and no dream could exist without its gravity, so each of us has a different use for what we remember. It is a brave fool who would venture back into the past with selfish intentions -- the watershed is an illusion and an avalanche5 can start with the touch of a butterfly's wings.

A million stars share in the creation of each wave in the sea and even' action of your own life creates a never-ending ripple6 in the pool of time. How would you or I know what to change?

When you peer into your past the view is surely clouded by a thousand crossroads and the trail of cause and effect has faded. The ink has dried but the shadowy chronicle7 of your past is a blur8 of random footsteps; we easily remember the highlights9 of our life but soon forget the million trivialities that are the brick and mortar10 of our existence. No, it is better to keep what you have and face the future.

Still, there is no harm in wondering what you would do if given one chance to change the past.