haxxiy on 11 December 2012
I'll go with Chrono Trigger theory of time travel.
So, time travels with you and the future is destroyed as you move back in time. So... you can go back from time X to time Y and prevent your past self from losing its leg and live normally from there. However, you still won't get your leg back, the timeline you belong is forever changed and your past self would disappear the moment the Y timeline reached time X so as to keep the amount of energy-matter constant; so you behave sort of as a very long-lasting virtual particle. And you then wouldn't exist in the new, rewritten timeline Y, time X until you came back to the future.
