Basically, this.Vigormortis said:Well, let's consider:
More than likely, ruling out dopplegangers, clones, hallucinations, etc, the reason you'd suddenly be facing down a (seemingly older) bearded version of yourself is because your future self went back in time with the intention of mugging you. For whatever reason.
Considering this, if you choose to fight back, we will have one of two scenarios occur.
In one, you will defeat your future self. This will lead to you likely realizing the futility of traveling back in time to mug yourself. Meaning, your future self will never go back. Which leads to a paradox.
In the other, you lose to your future self; who likely walks away gloating about the new found money he took. In this scenario, you may feel a need for revenge. As such, you may end up deciding, at some point in the future, to go back in time and steal the money you lost in your youth. This essentially closes the loop.
In effect, our choices are:
* Win the fight, cause a time paradox
* Lose the fight, allow events to pan out
So...yeah. Losing is really the only option.
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But, I actually take option C, and simply don't hesitate to give myself my money. The Pan-Chronodimensional Council Of Ieykes have an understanding. We simply cooperate with ourselves because we know that we know what we're doing and there's no reason to question my motives. If future me needs present me's money, then he needs my money. Simple as that.
Beyond borrowing money tho, future and present me are going to have some fun if we ever meet.
To answer the actual question tho, no, I probably couldn't beat future me, because future me would be the one with the element of surprise and a battle plan. I'd just be caught off guard.