"Unix compilers are slow. So to entertain myself while I'm waiting, I can play asteroids! You see? Compiler errors print out even while asteroids is running!" (2:05)
This was pretty revolutionary at the time, but for some reason those lines made me crack up. Also:
"Is graphics good for anything other than playing games?" (2:19)
The question sounded sort of facetious then as it does now, but for different reasons.