When I was about four, my family lived on the second and third floors of a three story house (another family had the basement and first floor). And I and my kid brother used to play in the front yard. One day I was playing in the yard by myself when a little girl who lived up the street from us stopped by (she was about six or seven). We started playing together, but after a while we got into an argument over a toy jeep (actually, more like a Landrover) that I had. It was painted a light green, had real rubber tires and was otherwise all metal (steel, I think). We both wanted to use it at the same time. Well, one thing led to another and she finally relented and let me have the jeep. Right across the bridge of my nose.
I spent the next little while (days or weeks--I don't remember) walking around looking like Rocky Raccoon. And ever since then, my voice has had a distinctly (and to me, annoying) nasal quality to it.
That was my introduction to relations with the fairer sex. And it's been all downhill ever since.