Prediction

 In a universe where causation follows fixed rules, memory is required in order to predict the future.  We must first remember that certain events proceeded in a specific order, after which if that string of events begins to manifest itself, then we can "predict" that the remembered chain of events will occur along with their effects.

So significant predictions require that we are able to recognize their preceding conditions and effects.  This is not easy if those events require complicated, subtle and difficult to measure causes.