"What, really?" replied Karyn, after Jon explained.
Then Jon said "I wish I would travel in time to the past" and disappeared.
Jon was standing outside his family's house in the past. It was late at night and everyone should be asleep. He wasn't sure that he should make the wish, but it didn't leave him any choice. "I wish that when my counterpart grows up and becomes me, he will make this sequence of wishes, including this one."
Although Jon wasn't sure whether he wanted to make the wish, the fact that he had made the wish in the past ensured that he would go to the past and make the wish. It was a time loop that he couldn't avoid; the wish itself, by time travel, forced him to make it and the next wish.
Then came time for the next one: "I wish that..."