"Nothing," replied Jon. "I just need to find something. A rock, long story... It's about so big..." He motioned with his hands.
"A what? A rock? It's probably on the floor somewhere."
Providing nobody stole it, thought Jon. And then he realized something else wrong with what had happened. He had wished that men would have vaginas and women penises... with as little else changed as possible. Clearly, transforming the lower half of the body rather than just genitals was not as little else changed as possible.
Except... there was a solution. What's the way to make men and women have different anatomy while changing as little as possible? Easy. Don't change anything at all. Go somewhere else where it's already true. Like a parallel universe--and the idea isn't any more impossible than magic stones.
If the only thing that happened is that he had swapped minds with someone from a parallel universe where anatomy was already different, then he would be on a world where men had vaginas and women penises--''without changing anything at all''. That way, there could be that change and the lower body change and any number of other "changes"--because they hadn't changed, he had just been taken somewhere where things were already like that.
That would also mean that places outside the wish area were "changed" because no change really happened at all--he was just brought to a place where it was already like that.
He wondered what the Jon of the parallel universe had done, but he bet that that Jon had wished to be in a world where men have penises and women vaginas, so they just swapped minds.
Unfortunately, if this was true it wouldn't be any easier to reverse. If the wish came true by putting him on such a world, then leaving the world would still be reversing the wish. He'd have to word the wish in some way that the first wish remains true even when he's back on his own world.
And first things first, anyway. He needed that stone. Could someone really have taken it? Who would know what it does anyway? Or could it really have just fallen on the floor, like the coach thought?