Great quote by Lasker

Education in Chess has to be an education in independent thinking and judging. Chess must not be memorized, simply because it is not important enough. If you load your memory, you should know why. Memory is too valuable to be stocked with trifles. Of my fifty-seven years I have applied at least thirty to forgetting what I had learned or read, and since I succeeded in this I have acquired a certain ease and cheer which I should never again like to be without. If need be, I can increase my skill in Chess, if need be I can do that of which I have no idea at present. I have stored little in my memory, but I can apply that little, and it is of good use in many and varied emergencies. I keep it in order, but resist every attempt to increase its dead weight.
You should keep in mind no names, nor numbers, nor isolated incidents, but only methods. The method is plastic. It is applicable in every situation. The result, the isolated incident, is rigid, because it is bound to wholly individual conditions.
— Emanuel Lasker, Lasker’s Manual of Chess