"Pain is the most powerful aid to mnemonics"

I can see how, tragically, this would be true and it is something you can see throughout history. One thing I wonder though is what would Nietzsche say to someone like Freud who claimed that we repress memories of pain. Or to more modern research (of course he didn't access to any of this...but just theoretically) that shows that we are more likely to remember happy things and that unpleasant memories are harder to recall. I think he might say that it is irrelevant because whether or not that N.'s theory is true, man has always used his mnemonic tactics as though it was.