Choosing one of the wishes he thought up, Jon said "I wish that for the next twenty-four hours, everyone in town would be part of some other kind of lifestyle or social group." Jon always wondered what things would be like if people (especially people he knew) would have led different lives. For example, would Sarah McMillan be nicer if she were a geek, or was she just inherently mean? This would give him the chance to see, without making it permanent.
Unfortunately, Jon didn't realize that everyone in town would notice the result of his wish, since this was actually The Obvious Stone. And people suddenly becoming part of some other lifestyle (even for just a day) would have seriously bad consequences, when they could remember how things were before the wish.
