Before writing, everything a culture knew had to live in someone's memory. Its history, its laws, its medicine, and its stories were held in human minds and passed by voice from one generation to the next.
Memory as a library
Oral cultures developed remarkable techniques for remembering. Rhythm, rhyme, repetition, and song were not decoration; they were storage. A story shaped into verse could survive centuries of retelling with startling accuracy.
Story as the carrier
Knowledge traveled inside narrative because narrative is what the mind retains. Practical information, such as where to find water or when to plant, was embedded in tales that were worth repeating. The story made the knowledge portable.
The shift to writing
Writing changed the terms. Knowledge could outlive its keepers and reach people who had never met the teller. Something was gained in permanence and reach, and something was lost in the living, adaptive quality of a tale retold by a person in a room.
What remains
Oral tradition never disappeared. It lives in family stories, in songs, in the tales told to children at bedtime. Every time you tell a child about their grandparents, you are working in the oldest medium there is.