It is true that knowledge transient time in language and writing. However, one must realize that writing did not come
into existance until later in the evolution of men. Art, often in the form of cave drawings, is what helped the modern
men in learning about the long forgotten past, during which there was no writing. With no language (as in speaking and
writing), men can still communicate through art, signs, and behaviors. A monkey can acquire knowledge by imitating a
human, such as learn how to use a certain tool, even though these two organisms are from different species and do not
share a common language.
As people have mentioned earlier, knowledge (and wisdom) is gained through experience and study, therefore, a single man
can still possess knowledge. However, as knowledge would worth nothing but to one himself if not shared with others, a
way to communicate with others is needed, which leads us back to my original arguement.
* This could go on forever, you know? There is never a true answer in philosophy. *