In addition to this, since we lose knowledge as well as gain it, we should add "YouCanForgetSomethingIfYouDontActuallyNeedIt?"ThinkingOutLoud.DonaldNoyes 20120501 Revisited.20130516
I remember something that someone, wiser than me did to break a young child's dependency upon a pacifier: " She took a pair of scissors and snipped off the nipple of it. When the child later on wanted to use it, she discovered that it didn't work. She brought it to her mom (the wise one) who said before the child could utter a word: "Oh look, it's broke"'' Amazingly that was all there was to it. The child understood "broke", and simply did not pursue the matter or ask for another. She really did not need it. It had only been a habit.
You can argue until you are blue in the face with someone, "You don't need this", but until they discover by some means, sometimes via assistance or intervention, or coming to themselves via self-realization, that they do not need the thing any more, thus they forget it. They do not remind themselves that they should forget it, (Don't Think about an Elephant) Instead, they stop!
Rote memorization vs. being able to reason something out or look it up: I've always thought that any brain cells spent intentionally memorizing something were wasted. If you use a fact often enough, it'll stick in your memory naturally, and if you don't use it often, then those brain cells would've been better put to reasoning and learning how to access stored data or learning other skills and currently relevant info. Thus for at least 70% of my life I've assumed that I can afford to forget anything that I'm supposed to memorize. So far the only negative effect that I've noticed is that I have to carry around a copy of my phone number (because I never call myself. I remember the numbers of anyone that I call regularly - or rather, my fingers do, I don't really think about what numbers they're dialing.) -- RT