What was the disadvantage of communicating knowledge orally?

Question

What was the disadvandage of communicating knowledge orally?

 

Answer 1

In addition to Matt's answer, the human brain can only store and recall efficiently a certain amount of information.  for example, whenever I need to perform, oh, say, a molar mass calculation, I sometimes need to refer to the periodic table, written information, to recall the mass of various elements that I haven't committed to memory.  Written language allows humans to conduct research.

Answer 2

Inconsistency. Information  can change with each retelling...