Once language starts to develop from about age 2, they do have a system for symbolic representation and can talk about things which aren't in their immediate environment including the past.

In the symbolic system of document transmitting, im age symbols possess a special transmitting power, and it plays a major role in the popularity of academic knowledge and the education of the masses.

When consumers begin to place emphasis on symbolic meaning of goods besides practical function, we have inevitably come to the consumption age.