Beginning of '95, even though I knew about it before then.
One of my good friends in college couldn't believe I got through my first year of college without an email account or a modem. But I kept telling him, "If I get it, I'll spend way to much time online." Jan '95, one of my engineering pre-requisites was a computer programming class, so I had to get one then. Plus, at the end of Jan I got a job in the university department that handled all the account maintenance for the university (via the same friend, he knew I was pretty knowledgeable about computers so he really couldn't understand why I didn't have an account).
So within a month I went from no account to having like 3, and being responsible for people knowing how to use email and surf the web and all that!