I think both of you are spot on. There's also the "What do I do now?" depression that follows one reaching a pinnacle of accomplishment.
Not for a moment wishing to compare myself to the crew of Apollo 11, but I know a little of this feeling.
I've mentioned this story previously, but I think it's worth repeating. I used to learn ballroom dancing (ballroom, latin and rock'n'roll). The studio I learned at held a couple of balls a year, which were a chance for students to dress up and have a bit of fun with their dancing; there'd be a live band, plus during band breaks the staff would play CDs of music we used at the studio, so we got to try out on a proper dance floor all the fancy steps we'd learned in our lessons.
But in addition to the general dancing, we could learn and perform routines. This involved selecting a piece of music and an appropriate dance, then getting your teacher to prepare a choreography. You then had 26 lessons to learn the dance with your teacher - not just the steps but making it look good too. Then on the night of the ball you performed the routine - 2 1/2 to 3 minutes of live choreographed performance in front of an audience of a couple of hundred, including plenty of people who knew their dancing.
The experience was pretty special. You'd start by discussing with your teacher a suitable dance and looking for some music to go with it, along with discussing ideas about how to present the dance (some students just wanted to do a dance, but others (including me) wanted the routine to include a bit of a story). The teacher would take the music and create a choreography. Then there'd be perhaps 8 to 10 lessons to actually learn the sequence of steps. The remaining lessons would go to refining your technique - styling, or changing bits of choreography if necessary, or working out little additions to the routine before the dancing began (as part of the above-mentioned story). At the same time you'd be looking for (or making) costumes and props. Then, about a week before the ball would be dress rehearsal, at which there'd inevitably be problems - some part of the costume would fail, or you'd forget part of the choreography, or you'd misstep and make a very obvious grimace. Finally there'd be the big night - butterflies in the tummy as your performance time approached, getting changed into your costume, waiting in the wings with your teacher for your name to be called. Then there was the performance itself - bright lights, loud music, the audience a blur as you tried to remember all the steps and styling, and at the same time try to make it look as though you were enjoying every second of it even as you felt a dull terror, adrenaline coursing through your body.
And then it would be over. You'd change back into your tuxedo or ball gown, slump back in your seat to watch the remaining routines, get your trophy at the end of the evening. You'd probably even head out to the night clubs for a few hours more dancing with friends.
The following morning? A huge downer. And I don't mean a hangover - I've never been a big drinker. It's just that you've invested months of lessons and quite a bit of money in the experience, and the pinnacle of that experience was a performance lasting less than three minutes, which hopefully went well (most do, but some don't). But after that there's virtually nothing. Yes, you'd get a trophy, and a few weeks later you'd get a DVD of the ball and get a chance to watch it all over again. But you never get to perform
that routine again;
that costume,
that choreography,
that particular set of circumstances - they're all history.
I still remember the feeling the morning after I performed my first routine: so strong was the downer that if I'd been told I would never be allowed to dance again I would have accepted it. (As it happened the staff at the studio were clever - they'd open the studio on the Sunday with biccies, hot coffee and a raw copy of the video, and try to lure people into signing up for another routine, a shtick which worked remarkably frequently.)
And in broad terms I think the comparison between the preparation for and performance of a dance routine and the preparation for and performance of an Apollo mission works well - the initial setting of the parameters of the routine/mission; training, initially in parts and then increasingly integrated and realistic; a final dress rehearsal; and then the actual event, taking a fraction of the preparation time. Using my own experiences as a guideline, I'm not in the slightest surprised that the astronauts experienced a huge downer in the weeks after their mission.
(And just to make a more direct connection, for one routine the music I used was Tasmin Archer's "Sleeping Satellite". For a costume I wore what you might call Mission Control uniform - dark pants, dark tie, white shirt with sleeves rolled up and with the Apollo 11 mission badge sewn on, while my teacher wore a typical late 60s miniskirt. For a prop we found an old radio sitting on a table. And to top and tail the music we added the voices of the Apollo 11 astronauts at touchdown and first step.)