As Dylan famously sang in the basement, "too much of nothing," can be a bad thing. Turns out too much of something isn't a good thing either. It's all about the portions. Sometimes the right amount of poison can actually be "good for you."
And I think as I once said, "too much of a good thing, can be a bad thing." According to Wm. Blake, "the road of excess leads to the palace of wisdom," but you know that little dude was kind of a joker, and that line comes from his little missile "Marriage of Heaven and Hell," and the quote is one of his Proverbs from Hell!
The road of excess can also lead to oblivion... and maybe sometimes it's hard to tell the difference between wisdom and oblivion, but I think there really is a difference!