1) When I was three, my parents just moved from South Korea to Buffalo Ny and I guess you can say one of our first memories together in America was visiting Niagara Falls for the first time.
2) The extraordinary circumstance would be that you would prpbaby never forget the sheer proximity, size, and roar of teh thudering falls...it all seemed imposing to me, especially since I was only three years old.
3) Personality-wise, I was a lot more blunt back then but now, I am more cautious in what I say although sometimes what I say means something entirely different to someone else. I think I am that same three year old if I try hard enough.
4) Most of my earliest memories has somethin to do with nature, first snowfall, Niagara Falls, outdoor wild safari, etc....
Your earliest memory is very similar to mine in that both of them were of a memorable place that we visited in our childhood. In my case it happened to be the Great Wall of China, but I think it's not very surprising that these magnificant sights were the first things we remembered, because you never really forget seeing such a marvelous wonder.