Why??

Growing up I was enamored with the concept of space travel. I wasn't necessarily a science fiction junkie, but a follower of the US space program. As each Apollo flight was headed to the moon, I was watching it on TV, reading about it in the newspapers, listening on the radio. (I even have - still - an autographed photo of Richard Gordon from Apollo12). So my kids know now that my favorite movie is Apollo13. When there is anything on tv about those days of landing on the moon, I'm watching it.

Well, recently there was a program on tv called "For All Mankind." It was a compilation of videos from the spacecrafts taken by the astronauts themselves. The program was also narrated by the astronauts. One made an interesting comment and I want the scientists to answer for me.
"When the sunlight shines through the blackness of space it's black. But I was in sunlight and I was able to look at this blackness. What are you looking at? Call it the universe, but it's the infinity of space and time. I'm looking at something called space that had no end and at time that has no meaning." In other words, he was in total light and yet in total blackness at the same time. How can this be??

Why?