Was it really 40 - 40! years ago?
The event we watched was the landing of Apollo 11 on the Moon, and the first 2 humans to set foot on a celestial body other than the earth. It was, I believe, the most significant event I've ever witnessed, on a whole range of levels.
It probably, for example, influenced me as to the direction I took when looking for a job skill (electronics), further heightened my interest in my favourite fiction genre (science fiction), also reinforced my respect for the USA. All of these important in forming a 12 yo's view of the world and it's/his future.
It was, I note during Australia's and the US's involvement in the Vietnam war. (It was pretty impressive that the US could wage a war (hot and Cold), and yet still do something the size and scope of what the Apollo project achieved). And I was even then aware of the technological spinoffs of the space program (transistors and integrated circuits, for example).
A few short years later, I was to join our Air Force and train in electronics, the way paved by the subjects I chose and was motivated in. A few years after I had left the RAAF I got to work manufacturing some space hardware (for a local subcontractor for what was then Hughes Aircraft - for the Aussat-B series of satellites - and a few follow-on ones as well).
So, as July 20th approaches, lets marvel at what was achieved, honour the courage and dedication of those that conceived and achieved it, and reflect on how it affected us all, in one way or another.