I think I probably first learned vi around 1985, in Boston, while working at CCA. CCA was a very interesting place for technology, as it was quite closely tied into the Cambridge tech world. For example, it was involved with computer networking in the 1960's, and was one of the 113 official nodes on the ARPANET. By the time I got there, the ARPANET had long been retired, and we were doing that weird UUCP thing, giving out our email addresses as things like decvax!cca!bryanp and the like. It is definitely strange to look back at how things were done then.
At any rate, although in my group we were doing most of our work on IBM mainframes, we had a number of community terminals scattered around which were connected to our Unix machines. I can't remember what version of Unix we were running on our machine then ... could it have been BSD Unix in 1986? I think so, maybe. Well, whatever it was, we each had an email account on that system, and could walk down the hall to sit at the machine and check our email and read Usenet, which was the 1986 version of surfing the web :)
So that was when I first used vi.
Nowadays, for the most part, I don't use vi, I use vim, which is the modern open wonderful version of vi.
Someday I'll go on and on about how wonderful vim is, but for today, what was wonderful about vim was its documentation. I had had a network glitch, which orphaned a number of my Putty SSH sessions, including several that were active in vim sessions. Usually this all cleans up automatically, but this time when I signed back on to the system and started some more edit sessions, I began to receive this message:
I checked my viminfo file, and it seemed to have the right permissions, so I Googled the message, and found that the vim docs had exactly the info I needed, together with a detailed explanation of how the viminfo file works, what it does, and how to handle its care and feeding."E138: Can't write viminfo file"
Most people that I know think that I'm nuts to still be using vim after 25 years, but: I know how to use it, it works, and I'm productive using it. I fear I'm unlikely to change.
Besides, the guy in the office next door (Roger) uses Emacs!