Of course, I already knew what a gnu was when I discovered FSF's GNU Project because I watched The Great Space Coaster as a child. I was thinking of this again today, and noticed that the show was on for a relatively short period of time (1981-1986) in my late pre-teens (compared to other shows like the Electric Company and Seasame Street, anyway).

Anyway, it was years before I understood RMS' joke/story about prounouncing the 'g' in gnu. Gary Gnu always pronounced the 'g', and since it was the first time in my life I heard the word, I never thought otherwise that the 'g' might be silent for some reason.