In a rejoinder to Pløn Verhagen, entitled "Learning theory or pastime of the self-amused" George Siemens makes the observation
"The content-central view of learning loses effectiveness in environments that are rapidly changing and adapting. Text in itself is a codification of knowledge at a point in time—a snapshot. In contrast, conversation is fluid and continual."
Knowledge is also fluid and continual, with each experience going towards our own sum-of-knowledge, but also having the ability to engage the mind in a bout of revisionism. We adjust our world model according to the latest information available (according to my empirical epistemology) - and the strength of this is such that we can suffer from source confusion (for a simple description, see Brewer and Williams, 2007).