This brings me to an interesting idea: many people constantly want what they can't have simply because they can't have it. It's like the "forbidden fruit" - the more it's off-limits, the more appealing it is.
I see the story of Tantalus all around me, day in and day out. People take advantage of something and then once it's gone, they keep aching for what will never be, even more so than when it was easily accessible. Why can't people simply accept what they presently have? I think it's the idea of "the grass is always greener" alongside with the "Tantalus" Principle, but who knows?