No I am not mocking your English. I said I do not understand your English. No mocking intended.
Here’s an answer to your question: It is my opinion.
There are in my experience VERY FEW GREAT memory courses available. But I have worked through a few and I can tell you that the following three are GOOD MEMORY COURSES I bought and used:
Dominic O’Brian’s Quantum Memory which I got from Audible,
Ron White’s Memory in a Month,
Course In Memory And Concentration - Dr Bruno Furst which I picked up at a local Charity Book Shop)
all of these had the same general problem… but the pros outweigh the cons if you are keen.
Before I tell you what in my opinion the problem is, let me say: ALL OF THEM HELPED ME. ALL OF THEM.
I really rate Ron White’s course (and Ron White as a person and memory man) although this early course by him suffers from being a bit too parochial (lots of references to baseball for example "Just imagine you are standing at home plate and some guy runs into deep left outfield" - that sort of stuff that was a bit troublesome to understand if you don’t know what baseball is … seemingly it’s some sort of what looks like the child’s game “rounders” played by grown men in peaked caps).
But it is a GREAT COURSE and if I were to recommend one to you that would be it…
Dominic O’Brian’s is another one I could recommend as it really does give a lot of detail but it took me months and months to go though. At that stage of my own journey I was interested in everything about memory techniques and this is a comprehensive course. The reason I got this course is that I thought O’Brian’s book “How to Develop a Perfect Memory” was the best book I had ever read on our subject. You might find it difficult to pick up a copy of that book but if you can get it and you are interested in Memory Systems in general - get it. As for the audio course: After a while I got a bit irked by his manner not his content. It suffers from constant unrelenting self-aggrandisement which day after day annoys … (don’t get me wrong he is good - at memorising and developing systems - but not at writing the script for a narrated audio course). Unfortunately, worse than that is that Quantum Memory is FULL of careless mistakes that should have been edited out after recording - for example he gives a mnemonic of the colours of the rainbow which is just PLAIN wrong… it should be ROYGBIV he ended up giving it as ROYBGIV (spot the difference!). There are also some rather ‘bawdy’ moments that well just make him sound like an old perv.
Bruno Furst’s course is interesting but I could only recommend it if you were only interested in how to develop your own system. It’s like a 1950’s mail order course.
Three courses three approaches no standard definitions or solutions.
And that’s the problem… there is no general standard nomenclature, taxonomy, notation or recognised authority for this subject of ours.
While Memory systems are veyr much like music or mathematics or language grammars - we have not yet been able to agree on standard terms or approaches or even definitions:
Fact: we do not have a standard notation, measurement criteria or difficulty ratings or - even one standard model for approach.
I think that we are at present about five hundred years behind music, three hundred years behind mathematics and several hundred years behind languages. I mean by that if I open any piano music book it is written in standard musical notation, key signatures, grand staff, standard clefs, time signatures and a standard pitch - you can write anything down using these standard terms and notations – Same with any maths book it uses the conventions of number and then arithmetic then algebra, geometry, trig, single variable calculus, multi variable calculus, statistics, probability logarithms… all built on each other - it is now a big collection of standardised terms which anyone who knows the language of maths can follow.
We do not have that in memory.
Because we have can’t agree. And most people writing generally about memory are amateurs (myself included and yes Francis Yates too and Dominic O’Brian and Ron White - we are all amateurs when it comes to laying out a standard step by step vision of how to communicate with each other about ideas… )
There is no standard notation for ENCODING (Systems), STORING Systems) , RETRIEVAL )Systems) … so each course is different as each author advocates different takes like the Dominic System version of a PAO, the Ron White version - in fact most of the real serious work on memeory is the development of competitive systems - not one universal ‘method’. At present - that’s STILL up to you.
Hope that helps!