How do you think people retained experience and knowledge in ancient times?

The experience could be passed orally from the elders to the younger, because society was very conservative, in India, for example, castes existed, so there were no problems with the transfer of experience. The son of a warrior (kshatriya) became a warrior, and the son of a servant (sudra) also became a servant.

In addition, knowledge could be recorded:

On papyrus in Ancient Egypt.
On an adobe tablet in Ancient Mesopotamia.
The Chinese also wrote down their knowledge in hieroglyphs and the Phoenicians in the first alphabet.
The Greeks used their own alphabet to record knowledge, which was quite convenient for antiquity.
It was possible to save records of knowledge in the library. The most famous was founded by Ashurbanipal in Nineveh.