There will be patterns on the surface of the jelly, low spots where the drops settled. This, according to de Bono, is memory, something that has happened and not completely unhappened. Today, when you drizzle water onto the surface, the flow of water will be affected by what happened yesterday. So the order in which patterns are presented determines which grooves get established. The book is filled with such writing about happenings on surfaces, happenings which harken of mental experience.
Thoughts flow in learned patterns.
And the more those patterns are etched, the more difficult it becomes for later thoughts to find new patterns. Events which differ from existing patterns nonetheless tend to flow into the established grooves. This model of mental mechanics suggests techniques for getting unstuck, and de Bono, in most of his work, explains these techniques again and again. He suggests ways to jump out of the groove, to enhance the possibility of finding a whole new avenue. Selecting a word randomly, say by poking your finger onto a printed page, force your thoughts to find connections between that word and the problem you face.