How do we accumulate knowledge?

Since the internet exploded, much of our combined knowledge is available to the average person with internet access. But it is not just about availability though. Information is fed to us [emails, facebook, blogs, news articles] at an unprecedented rate with most of it random, subjective and noisy.

The sheer volume of incoming information means that we hardly have the time to make our own evaluations. So we outsource it. Consolidating information and making it consumable is becoming a big business these days and the loudest (not the best) information gets most attention. Is this healthy?

What exactly do we remember once we finish consuming a certain piece of random incoming information? Why do we remember that? Are the reasons satisfying?