I was still only 6 years old when the original series ended, so I didn't see it
during its initial run, but I watched plenty when it was put into syndication.
I even watched the short-lived animated series. (1973-1974, I think.)
On a somewhat related note, have you heard of the prog rock band Spock's Beard? Not surprisingly, they got the name from that same Star Trek episode. When they were trying to decide on a name, one of the band members threw it in with the other possibilities as a joke, and it ended up being the one everybody liked the most.