I hate teaching the kids binary extremes, because when they grow up and realize it's bullshit, they have no yardstick for measuring what *is* reasonable or not. And they tend to wonder if *everything* you've said is bullshit. But I digress.
One of my favorite phrases is "it's the dose, not the poison."
There's all kinds of things that if you have a little (relative) there's no harm. If you have a lot (relative), you're toast.
It's so hard to get across though with the fear monger society we have though.