Two weeks ago (July 20th) was the 45th anniversary of the Apollo 11 moon landing and mankind's first step on the lunar surface when Neil Armstrong was the first of two astronauts to step outside the spaceship.

There are those who contend that this event was all a staged fabrication.  That no human has ever traveled to the moon.  It was all an elaborate hoax.
They'll point to the fact that we've yet to return to the moon or to go beyond in space as "proof" of this notion.

Personally I think the reason we've never gone back is because we actually DID successfully land on the moon, and that what we had to do in order to achieve that goal took such a big plug out of us as a society we've never recuperated from the effects of all the "Peters" we robbed to pay this humongous "Paul".  I suspect a lot of the economic problems we've been plagued with for so long originated with the expenses of that project, including: the shortages in remaining funds for social security; the highway funds reserved for road and bridge repairs; the funds needed for infrastructure maintenance; the Medicare/Medicaid funds; etc.
And no telling what the environmental effects are. The hole in the ozone layer? The dwindling fossil fuel resources?

You'll find that when something exceptional is brief or short-lived it's usually from being so high-maintenance in nature that it's creators, owners, curators and overseers eventually get burned out from the complexities involved in keeping that project going continuously or indefinitely.  (Maybe this might be what happened with The Beatles' career as a group.  Or with the old traditional top-40 radio formats of the 1950s/60s/70s.  Or with the original "progressive rock" format.  Or with the big band era, or even the progressive jazz of the 1950s and '60s.)