2 years short of 40.
So, yes, it is possible to still be a CAG after 25.
When I used computers as a kid, they were called teletypes, and they printed like a typerwriter to large rolls of newsprint. Programs were stored on ticker tape. Modems were cradle like devices that you put a phone handset into--remember, back then almost all phones were the same style. Games consisted of a text version of Trek and Adventure, Mugato, and variations of tic-tac-toe. Computer graphics consisted of ASCII posters of the Starship Enterprise.
I remember when one of my friend bought a Sinclare (?) kit, and my school had "IBM Pet" computers and dummy CRT terminals.