Re: Only four left
There's another eight left that have been out at the Moon, but not landed/walked upon it. They've also got some stories to tell. Al Worden tells of retrieving some film and being out in a spacewalk with the entire Universe before him.
Frank Borman, CDR Apollo 8
Jim Lovell, CMP Apollo 8 and CDR Apollo 13 (twice!)
William Anders, LMP Apollo 8
Thomas Stafford, CDR Apollo 10
Michael Collins, CMP Apollo 11
Fred Haise, LMP Apollo 13
Alfred Worden, CMP Apollo 15
Ken Mattingly, CMP Apollo 16
I figure that Jim Lovell is actually the one person that's been further from Earth than any other individual. He let the other two on Apollo 13 look out the window at the Moon's far side, so he would have been on the other side of the CM, ever so slightly further from the Earth than the other two. FTW.
(Apollo 13's Free Return Trajectory was the furthest - "highest" - from the Earth. I'm adding another layer of detail to the title 'Highest Human Ever'.)