My then employer, Bell Laboratories, trained me to use their Unix operating system in '79, with a terminal and modem on my desk. All of their computers were interconnected in a corporate LAN, so I was able to use internal e-mail to contact others, and to access a limited number of games that they'd loaded for people to use.
A couple of years later, all the company's computers got hooked up to DECNET, which was a kind of bulletin board/affinity group network, for all Digital Equipment Corp. computers around the country. It was like the Internet without Graphical User Interfaces. Suddenly, everyone in the company was spending hours a day posting on their bulletin boards and sending/receiving e-mails. So much productivity was lost that the company abruptly unhooked everyone.
I got computing at home at the same time--first a Texas Instruments Silent 700--like a portable typewriter with "muffs" to accommodate a telephone handset; then a HP 2621P terminal with external modem hooked into a corporate LAN. The company gave me my first PC in the office and at home in '87, but it didn't run Windows. That came two years later.
I started up an AOL account around '93. My first chatroom was a site for '50's and '60's music--a highly competitive quiz every Friday night. Lotsa fun. I've been a Web junkie ever since.