I've seen a lot of baby clothes with things written on them like, "accident" or "the condom broke" and so on. Once I saw a toddler with, "I'm a bastard but my mama loves me anyway". Am I the only person who finds these things grossly inappropriate?
Oh, and on the deionised and distilled water thing: deionised water is expensive, yes, and not necessarily clean to drink (although it was probably fine if it was in a lab). Water normally has a small amount of dissolved minerals etc. in it, making it isotonic with our cells. Purified (i.e. distilled) water has almost nothing in it, so it can theoretically cause trouble. However, there is actually very little difference between the two, because tap water has such a small concentration of solutes to start with. And almost no foods or other drinks are isotonic anyway, yet we can eat/drink a fair amount of them without any trouble. So a glass of purified water won't do you any harm just like a glass of milk or apple juice is harmless. Actually, drinking too much normal old water is bad and can cause death (dilutional hyponatremia--look it up). Purified water is just the same, although it takes slightly less water to do it (i.e. a few percent). In the end, though, we are still talking litres and litres, and the difference is negligible at that amount. It sounds a lot like the teacher was stretching the truth, honestly didn't know or had misinterpreted something, or was trying to stop students wasting school money by drinking water that was expensive to purify/deionise.