The idea behind the octopus is that the octopus has the most complicated brain of all the invertebrates. The octopus nervous system has about 500,000,000 neurons, with two-thirds of these neurons located in the arms of the octopus. Neurons in the octopus brain are arranged in lobes and tracts that are more specialized than simple ganglia. An octopus has a "good" memory and can also learn and predict..