When I was younger we got our first microwave and I spend the whole day microwaving things like a high-tech pyromaniac. I watched a CD turn into sparks, observed as bread turned into charcoal, and saw how paper...uh...stayed paper. With solid objects out of the way, I decided to microwave some water until it turned into steam. Not satisfied, I moved on to microwaving soda until it bubbled intensely. Playing scientist and curious about my "creation," I decided to taste it. I suppose my logic at the time, being as young as I was, was that since water cools you off then water can't ever be hot...or something like that.
The reason why doesn't really matter, because I immediately burned my tongue, dropping the boiling soda all over the floor as I recoiled. For about four days I had unbearable pain unless I kept an ice cube in my mouth, and I had trouble speaking for about two weeks. Even now, dentists note that I have unusual scarring on my tongue that I feign ignorance for. Actually, on reflection, I guess a burnt tongue could explain my high tolerance for spicy and sour foods.
Anyway, that's tied for an equally stupid idea around the same time where I dropped and watched water sizzle on a piping hot incandescent bulb. At a certain point the bulb literally exploded with a violent shatter which even today I'm surprised didn't manage to harm me.