Knowledge not recycled into the common knowledge base is lost forever. What a shame to lose so many learning fragments! You may know something that nobody else knows and there are so many places to share your information. Facebook, YouTube, even Urban Spoon (if you know of a great -- or not so great -- restaurant).
Listening to Betsey Sparrow from Columbia University who was speaking at Learning 2011, she describes it as "Transactive Memory". Simply, we use our friends, family and the Internet to help us remember things that we forget.
Although some may say that Google is ruining your memory, we look at it as a vast recycling center of trillions of pieces of knowledge that you couldn't possible remember anyway.