The butterfly effect

The butterfly effect or chaos theory describes butterfly effect as
"Small variations of the initial condition of a dynamical system may produce large variations in the long term behavior of the system"
I was watching the movie butterfly effect in which a very small change made in the hero's past changes his future in a huge way.

One of my friends told me that he just bumped into an old classmate from Junior college on the road and now, they are about to get married soon.
Another one had nearly missed his interview for the company where he is doing absolutely great.
Someone just had a awesome idea which made him millionaire.

We can easily find some defining moments in our past life which has resulted in the present as it is. How would the present be if such small things had not happened the way they have?

For me, such defining moment came when despite the high fees (for my economic state as that time), my parents agreed for me to attend Jnana Prabodhini. I would have been much different person if I had not been in Prabodhini.
Another one should be when I got posted in Chennai, which I had absolutely never expected (I still dream of working in Pune :)). It was a shock, but I did OK there and that gave a lot of confidence. I feel I am a much matured person after my Chennai days.

Well... sometimes I think, give a change, whether I would change something in my past... I am still confused about this....
There are always some incidences which always feel totally negative. May be there are some in my life too...
But would I like to change them? And If I do change them how would it affect my present...?
I still have a lot of thinking to do....