There were three astronauts on the Apollo 11 mission. Most people can name Neil Armstrong and Edwin "Buzz" Aldrin but many would be hard pressed to name the third man, Command Module Pilot Michael Collins.
Twelve men have walked on the Moon but only seven have orbited the Moon alone*. Collins admitted that he didn't have the best seat on the flight but it was still an honor to be part of the Apollo 11 crew.
As he wrote in his autobiography, Carrying the Fire: An Astronaut's Journeys:
This venture has been structured for three men, and I consider my third to be as necessary as either of the other two. I don't mean to deny a feeling of solitude. It is there, reinforced by the fact that radio contact with the Earth abruptly cuts off at the instant I disappear behind the moon, I am alone now, truly alone, and absolutely isolated from any known life. I am it. If a count were taken, the score would be three billion plus two over on the other side of the moon, and one plus God knows what
on this side.
*John Young on Apollo 10 is the one you're probably forgetting.