I was 15.
We had moved to Florida in March and I was back in Massachusetts for the summer, helping my aunt, who had just had her 3d kid. She had to go back to the hospital for some kind of surgery, so I was watching with my uncle, also on a black and white TV. He was going nuts, like it was some kind of science fiction story, come true. I was probably watching through some kind of drug induced haze, and I couldn't figure out what the big deal was .
In retrospect, it's a very bittersweet memory for me. My uncle (by marriage) died when he was 52 and since he was the one that kept my aunt sane, let's just say things were never the same.