Jon understood what the stone meant now: something interesting did happen, just not to him. But the range of the stone was limited, so it probably happened to someone in town. Jon didn't remember anything being out of place, but he wondered if that was just because he accepted the interesting thing as "normal" in this new reality. Or perhaps he didn't run into the person. Either way, he felt guilty for potentially messing with someone like that.
He was about to modify the wish so the interesting thing happened to him when he paused. Maybe it was a good thing that happened? Maybe he should see what the change was first before deciding. And who was affected by the change anyway?