Haha one of my only memories of kindergarten was one naptime my cot was next to a wall receptacle without a cover. My perception from this great temporal remove is that the shock was much less severe than others I've experienced since, perhaps because the fabric cot insulated me somewhat. [EDIT:] I've sometimes wondered how many other children were shocked by that particular outlet, given that there were fifty children in my class. Presumably most of us were only shocked once...
Nearly caught my bed on fire by not understanding that a battery-powered motor isn't going to spin faster if I plug it into the wall. It even dimmed the house lights enough for my dad to come into my room to check if I noticed it too. I pretended nothing had happened. No one ever noticed the singed hole in my sheets.