Patterns are conceptual models that isolate the design from its implementation.

They belong to the highest level of abstraction, in the same real as metaphors.

They are extremely useful to synthesize a complex idea.

They are a form of intellectual alchemy, as there has to be a limited number of patterns, which one can find and catalogue. Being literate on patterns could allow you to synthesize anything, to design anything. The rest are implementation details.

Patterns are related to the concept of emergence, in that emergence seems to happen by applying a limited number of patterns over a limited number of components, and that creates a new breed of more complex components operating at a higher level. We could consider emergence itself as a pattern, actually one fundamental natural pattern.

This Labyrinth is nothing but a pattern, for instance.