Remarkable how many original Star Trek episodes were, in essence, remakes of Joseph Conrad's Heart of Darkness. And how many seemed designed to illustrate Chesterton's observation:
"We are all under the same mental calamity; we have all forgotten our names. We have all forgotten what we really are. All that we call common sense and rationality and practicality and positivism only means that for certain dead levels of our life we forget that we have forgotten. All that we call spirit and art and ecstasy only means that for one awful moment we remember that we forget.”
Or as Walker Percy put it in Lost in the Cosmos:
"Why is it that of all the billions and billions of strange objects in the Cosmos -- novas, quasars, pulsars, black holes -- you are beyond doubt the strangest?"
This is why it doesn't matter that the original Star Trek had laughably crude technology and special effects. It asked the right questions.
And that is why, despite his talent, Mark Twain finally tires me. He talks so well, but in the end, has too much and too little to say.
The various iterations of Star Trek often give us an opportunity to observe human behavior through the eyes of aliens (Spock, Tuvok, Worf, etc.) or artificial intelligence (Data). This gives us a necessary tool for thinking about ourselves: contrast.
Again and again, Kirk or Spock lose their minds, or have them stolen, or are split into two beings, or stranded with amnesia on a planet, or some other character cannot say who he is, or is found on another planet not quite himself, fabricated perhaps from memories by aliens.
"Who am I?" is a constant theme of the original series.
Although I like Picard and find Data a gentlemanly cyborg, the later Star Treks lose me quickly.
The original series was either Paradise Lost in outer space or Gunsmoke in outer space. The secrets of its success were that it relied upon archtypal human stories, AND the strange and dynamic form of human friendship called the brotherhood. TNG lacked that -- it was not Gunsmoke in outer space, but the faculty lounge at State University in outer space.