A life lived at full throttle can't be sustained. Eventually we start calling it a night and asking for the doggie bag after a couple of rounds. We begin feeling more sorry for than envious of Charlie Sheen. But what about overindulging in the stuff that seems so good for us? Sleep, for instance. Or coffee. Or antioxidants. If those things are inherently good -- even lifesaving -- can't we just gorge ourselves on them? After all, who ever heard of someone going on an antioxidant bender?