Fischer was messing with Frank Brady's head.
Fischer & MCO

Seeing as how Fischer despised modern chess opening theory, I'm willing to bet 50 bucks this was sarcasm.

For those beginners (or any level players) who want to be super-GMs and devote lots of years to chess, they'll probably have to learn openings to that degree anyway, so maybe Fischer was correct, insane hateful prick that he was.
Then again, maybe he was so close to the top in the 1960's and finally at the top in the early 70's for a long time and from such a young age, that most of his wins (and losses) were based on the minimal advantage of remembering a large volume of specific opening sequences. For instance, he had a winning position against Botvinnik when Botvinnkik was champ in the early 60's and blew it and got a draw instead. I imagine there were few very obvious mistakes, so if you asked him why he blew the victory, he wouldn't say "I wasn't tactically strong enough and need to do more training", even though without super-GM-level tactical skills, he never would have been that close to victory, nor would Botvinnik been able to have secured the draw without super-GM tactical skills, but would have said "My endgame study/technique helped", even though he wouldn't have reached such an endgame without being able to identify and respond to complex tactical threats with every move.
What do you think of this:
"For the first lesson, I want you to play over every column of Modern Chess Openings, including the footnotes. And for the next lesson, I want you to do it again"
(Advice of Fischer to his biographer, Frank Brady, who had asked for chess lessons)