Mary Ruined his life with her wish
When she threw the stone at the old house she clearly wished that he would not travel and have adventures, but would stay and marry her.
Selfish.
Her wish may have been selfish, but it was only a wish. To paraphrase Raj Koothrapali - it wishes came true, most men would be well hung billionaires with wings..
George ruined it: you're not supposed to tell your wish or it won't come true: he told Mary every bit of his wish. Mary, on the other hand, reminded him that telling would cause the wish not to come true. She kept silent, he was expansive.
So, well....
If we go by the rules of wishes - you're right!