[Captain Peter Blood]

The reason I think most of the astronauts that made the trek to the Moon and back and have so little to say is that from what some of them have said in the past it was the most Humbling experience ever in their lives.
Most of them have had a very great religious experience from it and consequently have had very little to say on the subject.
It is almost akin to those who are Medal of Honor Recipients, most of them never talk about their experience's and how they came to get such a medal.
Same with these guys, essentially what they did was a "suicide mission, they did their deed and came back alive.

[RightWhale]

Besides, most were engineers or test pilots, people who are not known for idle talk.

[taxesareforever]

I don't believe that explanation at all. Everyone has humbling experiences and they do talk about them. Otherwise you wouldn't know about them.