[@Zeroth] I won't lie, a character like that is going to have issues. If the only thing he is able to remember is "stop Ganon" does that mean he literally can't fight anymore or navigate his way around Hyrule because those are skills he forgot? You'd have a very rough time at the start, the character would practically be unplayable. Consider that the only way into the Sacred Realm is the Temple of Time, meaning that's where you would exit from as well. The Temple of Time is in Castle Town... which is basically the exact center of Ganondorf's forces. You'd start out exactly on his doorstep practically, not to mention being absolutely surrounded by hostile forces out for your blood. No one's coming to save you, either, since they either have problems of their own or they will start out in Oasis and be too far away to help you in any way.

Not saying it's impossible, but I am saying that you will almost certainly not have much fun being so trapped behind enemy lines and with no one to help you or interact with.