I learned a healthy respect for power tools from my dad. At 10 I was working his 1936 Craftsman lathe, turning out spindles for a coatrack he was restoring, and did a few candlesticks as gifts and the like.
Woodshop in junior high - 13 years old - made a lamp in the shape of a waterpump (you pushed the pump lever to pull the chain to switch the lamp on and off).
So I also know how to wire a lamp, and decided to fix an old one with a bad socket. There I was, with a lamp cord. Stripped a few inches off the end, and thought, "Well, the wire in the bulb gives off light, I wonder..."
Plugged it in and touched the wire ends together.
When I could see again, there were no wire ends, and a 3" long scorch mark on the hardwood floor.
Sometimes, one only learns by doing. Despite my understanding of danger, power tools and how electricity works, curiosity got the better of me. It's the age, and I took one more thing out of my bag of luck, and put it into my bag of experience. I've had a few minor jolts since then working around live wires, but I have a much healthier respect for them.