When I was about nine I hit a cricket ball under the neighbour's fence, we lived on a farm in Woop-Woop so this fence happened to be electrified to keep the cattle in. I didn't know this, and needles to say I got stuck in between the wire constantly getting shocked in the back for a good five minutes. "Get mum OW! Get mum OW! Get mum OW! Get mum OW!" My sister thought I was just joking, so she didn't get mum.
Probably the most traumatic thing of my young life was when I was chased by Papua New Guinean Mud Men during Tribal celebrations. There was a lot of yelling, mostly by the highlanders, and also a lot of crying and running, mostly by me.
Reasonably frightening for a five year old.