Each of those things are incredibly different, but what is felt by the people when they lose 'THE THING' they think defines them... is the same. And each and every one of them, as part of the process, will try and convince you why, "no, it isn't like that for me... it's different for me, there is no way you could possibly understand... you just don't get it."
Well...it IS different for me, and you aren't getting it. And I will attempt to explain why.
I think one reason why its hard to explain this whole thing is that the subject of "aviation" is something that very few people know much about...but everyone has an "impression" of it, (how things "work", what its like, etc, etc) and those impressions are mostly wrong. And because its not quite like anything else, its hard to draw analogies...but here goes.
The other examples of "losses" that have been given are not the same, because, as I stated before, what was lost was something that is known to only last for a limited time. They had something that they loved, but knew far ahead of time that it would end. Nobody spends 40 years flying fighters. Beauty fades. Here's another more common one: Many (most?) women mourn the loss of their fertility at some point, but it is a normal an expected passage. Women who have born multiple children, as many as they ever wanted, and absolutely, positively don't want to have any more, become depressed when they lose the mere ability to have more. But those people all "got to be" whatever it was that defined them, for whatever period it lasted. None of these people were "ripped off". They had a "loss" to mourn, but its a different kind of loss. Or, perhaps you could say that what they had is a "passage".
The only thing I can come up with that people might understand is by using a sports analogy. Like flying, its something that very few people get to do, and is very "prestigious", and its something to which most people who do it, aspire from a young age, if they have been born with the appropriate gifts...but unlike flying, everyone understands it, and has even done it, on some level. So, imagine a minor-league pitcher, a "hot prospect", taking the mound on his very first professional game. Before he gets to throw his first pitch, some nut comes out of the stands with an axe, and chops his right arm off. that's it...game over. Career over. But its a career he never really "had", so he can't move into what other ex-jocks do. those things require you to "have been", and he wasn't. Yet, he spent his youth doing lots and lots of "stuff" to get to this point of "almost there", focusing totally on this one goal, to the exclusion of any other. Sure, most of these guys go to college, but what do they study? Of what vocational value is it, should the sport disappear? not much. So, now what? It took a long, long time for me to find another path. But don't kid yourself; nothing is going to replace "pro ball". And thats what flying was, to me. So to answer your earlier question, yeah, I did some flying. kind of like my ficticious pitcher... "I played some college ball". And I was good enough to make the big-leagues, but I was robbed by a freak occurance of fate. (and that feeling of having been "robbed" is probably the source of the anger that you sense).
on the "astronaut" thing: that's different, too. sure, "how do you top walking on the moon"? Sure, I get that, but its dillema of a different sort. First of all, only 12 humans have walked on the moon. This is not a realistic career aspiration for anyone. These guys were all at the top of their field, before they undertook this task. In my analogy above, they were 10 year pro-veteran ball players, and were selected for the "all-star" team. Sort of. they have an all-star game every year, and the Apollo program was kind of a "one time thing". but the point is, they took the opportunity when it presented itself to them, but its not something
