A lot of people are bothered by the idea of biological determinism – the idea that given the genetic hand they’ve been dealt, and the environment they experienced, their path in life was essentially inevitable. When you consider the fates of identical twins raised apart, particularly examples like the Jim twins, you can feel boxed in. In a philosophical sense, that is: you are probably thinking too hard if the the fact that your non-existent clone might have gone down much the same life path as you engenders weltschmerz.
If it does, though, there’s a way out of it. Find a situation with at least two alternate courses of action that are sure to lead to wildly different outcomes, and make your choice based on a truly random event, such as nuclear decay. Even if your clone did exactly the same thing, there’s no way of predicting what path he would take*. If you’re feeling wimpy, you can restrict your paths to ones that don’t have a high likelihood of immediate crucifixion.
On the other hand, if you are truly determined, you can pick paths that are chaotic as well, so that infinitesimal difference in your initial actions will eventually lead to big differences in your trajectory. In that case, though, all bets are off.
I’m thinking that there’s probably already an app for this.
*unless the Everett-Berra theory is correct.