Are spirit guides and the higher self allowed to help a person remember things they have learned? Can students request this help and get it?

Indeed, this can be done and will powerfully expand learning. This is not cheating. After all, the idea that people have to retain information and cough it up for passing exams is a primitive idea of education that is based on authoritarian oversight and over-attention to the most mundane of cognitive functions. It is much more educational to give students an entire array of resources and ask them to create something. Then the mind can do something of true value and will be able to demonstrate its grasp of ideas, which is a much higher level of performance than coughing up information, facts, and figures.