Memory system to memorize openings

This specific  0-9 mnemonic code system has been around for ages. I used it since I was 9 years old (TeN MoRe LoGiC FiBS was a mnemonic to remember said mnemonic) and I picked it up from a book on memory power.

It was quite useful for parlor tricks (memorizing the periodic table,  rattling off big 100+ digit numbers or even cheating at cards!) and I still use it to remember people's phone numbers.

HOWEVER ... I don't think there's a return on investment for chess, which actually demands a comprehensive (read => Learning, not Memorizing!) skill set in order to get any  good, not just a crib sheet.

Isn't it obvious that your opponents can deviate from book and then you're on your own?  Why invest a ton of time playing the opening like a 2400+ player when the rest of your chess may be 1200-rated?

I'd rather use that time to learn how  play the entire game of chess like a 1800-2200 player.

Memorizing openings to the exclusion of all else is bad; not also learning other aspects of the game is bad; not understanding the middle game positions is bad; lots of things are "bad," but memorizing opening variations is not one of them in and of itself. The problem is you're making an assumption. Memorizing lines does not necessarily mean you do not understand positions. So, the point you are trying to make is not well constructed. Okay. Have a good day.

You have to react to your oponent=It good to have the correct moves to respond=your unsdanting of all movres is needed