Wine is a time bomb that you set off by opening. If you drink only a glass or two from a bottle the night you open it, chances are the remaining wine will be undrinkable, or at the very least not worth nearly what you paid for it when you get back to finishing it. And the more expensive your wine, the worse this phenomenon—both because better wines seem more vulnerable to the ravages of the demon oxygen, and because every glass of the pricy stuff wasted is that much more of a hit to your investment portfolio than if you settled for Two Buck Chuck.