Not counting the ones I worked with Dr. Naismith, here's mine.
The park district in the Chicago suburb in which I lived decided to start a rec program for Jr. HS boys. They asked those of us who had umpired park district baseball the previous year if we "knew how to referee basketball". I had worked baseball for all of two years and I told them "Sure, I can work basketball." All I knew about the game was what I had seen on television and in watching my HS games. This was January of my junior year in HS.
My first game was between two 7th grade teams. I was partnered up with another HS kid. The games were played in a gym at city hall, which originally was the old high school building. I remember I had a blue whistle I bought at Woolworth's. The park district gave us some striped shirts and we wore blue Levis and white high top gym shoes. We did the best we could and there really weren't many complaints at all. I do remember calling a shooting foul on a missed shot right before the end of the game when the game was tied and the kid made one of the free throws. Hey - NO OVERTIMES - even then.
BTW - this was 1964.