Did you ever think that on going back to a choice made in the past and choosing the opposite, the results to your life would have been different ? Somewhere in your life can you pinpoint an event which defined you and your destiny depending on which path you chose to follow ? Or in spite of said choice, do you think things would have turned out pretty much exactly the same now and that where you are and who you are were pretty much calculated as an extrapolation of probabilites with any choice you made merely being an uncertainty factor with little relevence in the overall outcome ? That is too say, you would have made another choice later on which would enact the same type of event leading to who and where you are now anyway ? Bear in mind your 'fate' as it were is so intertwined with others that any choice you made, to have any lasting effect, would need to have the appropriate choices made by a whole host of others to change an event.