It was at the Consumer Electronics Show in 2001. I was wandering around the Central Hall, minding my own business, making my way through the massive, packed crowd of 250,000 people.
All of a sudden -- WHAM, I was knocked to the ground. (Okay, that was for dramatic effect. It was more of a "Thud, I was bumped to the ground.) Turning to look up, I saw one of the Segway electric vehicles that had just been introduced a month before.
Anyway, standing on the Segway was a sheepish Jeff Bezos, someone quite wealthy enough to have bought an early vehicle. (60 Minutes said his wealth is estimated at $20 billion.) He was very embarrassed, and apologized, and I laughed it off. We traded a couple quips about tumbling over, and that was it. He scooted on.
To this day, though, I know that if I had flopped around on the ground and writhed in pain, grabbing my neck and hollering "Whiplash!!" with agony in my voice, I might right now be writing this from my private island in the Caribbean.