Knowledge of the stone

When Jon got to his room, he immediately pulled out the stone. ' He sat on his bed, tossing the stone between his hands as he thought of what to do next. ' He suddenly realized, that though his grandfather had told him everything he knew about the stone, there might be other things he didn't know. ' Jon could the stone itself to fix that.
"I wish that I knew all of the rules and workings of the stone." No sooner had he said that, the entire wold went black.
Or at least, in the normal sense. With a completely different sense, he could see all of the possible realities, going off in the distance into neitherness. Jon had a strange suspicion of what had happened. He thought he had become the stone. Either way, the wish was granted. He now knew everything about how it worked.' 
Apparently, the stone used trigger words (it could understand all language) so that it could find an alternate reality that fit the description. The trigger words "I wish" were used to signify that a reality change was necessary. The reason the stone couldn't reverse wish was because when it made the wish a reality, it changed its own memory so that it couldn't think up a reality that went back on the previous changes. ' With Jon now the central command of the stone, he could now use his new powers to undo any wishes. ' But first to give himself a animated body. He knew from the stone's knowledge that the old reality was still around him, he had just disappeared from it. In his thoughts (since that was all he needed to make wishes) he wished. "I wish that I had a body desirable to me." Instantly, the myriad of worlds narrowed down to a countable number of possibilities. ' Suddenly, Jon realized his mistake. he had wished for a body desirable to him. Most of the available realities were of various females that he would want to do. He wanted to take time to think about this, but he felt a pressure to choose. ' He didn't no what to do, so he just picked one.