Frederick Bartlett introduced the notion of schema to explain the results of his Cambridge story-memory experiments. Bartlett suggested that people come to such experiments with a pre-existing notion of what a story should be like: a schema for stories. The positive contributions that schemata make to memory are also obvious in a different area. As all cognitive psychologists know, experts are far better than novices at remembering material from their fields of expertise. Memory for both poems and chess positions depend on certain cognitive structures so called schemata that exploit the constraints and regularities of the genre. It is because the schemata of experts are rich and elaborate that they have good domain-specific memories. Autobiographical episodic memory doesn't suddenly kick in at age X, having been utterly absent before; rather, it develops. The cognitive structures that enable us to recall life experience differ from the schemata of poets and experts in one critical respect.