to live it or not

Ever heard of this theory:

The world that you are living today, is one of several possible worlds. At each point in time you do something that that decides the next reality along the time axis.

If not from philosophical readings, you might have come across some variant of this theory in movies (seen timecop..). Well I got fascinated by this theory from a Deepak Chopra novel (The return of Merlyn). The wise wizard Merlyn is trying to teach his young apprentice how to control which possibility will become reality in future.

I came across the same theory again from Richard Bach, another of my favourite authors. His books always border on physical and metaphysical worlds and he takes you with him so effortlessly that you start getting addicted to his books. In the book I am talking, he is taking a trip with his wife and travels along the time axis to a point when they cross each other’s path for the first time. I believe the book was The Bridge Across Forever in which he primarily focused on their relationship and his concept of soulmates.

Ever thought what it would be to go back for sometime and relive some parts of life. Or may be walk down one of the possibilities that did not happen. Bad question I guess, because all the people do it sometime or the other. Some we call Day dreams and some just dreams and the not so pleasant ones as nightmares.

And what if you have to live through the reality as if you are not what you are now but a different possible existence. Something that you did not become but could have. You might enjoy it or may be it would too difficult to bear to see what you lost.

Say for example you always wanted to be an explorer/nature photographer (Or may be the prince or CEO of your company) and you get a chance to just that for 2 days courtesy some friend... will you enjoy it thinking you have finally lived it.. may be for 2 days but you have lived it. Or will it make you sad because you have just had a taste of it and realize what you have missed.

Ever thought, is it wise to take up such opportunities when life presents them to you?
Ever experienced this?