The content is quite interesting but I have a question about his use of the plural of octopus. He uses three (3) different words for the plural: octopuses, octopi, and octopus. According to my American dictionary octopi is incorrect but then the narrator seems to be British so he may be having some fun with the Americans in his audience. This is not a major problem since the subject of octopuses arises only rarely among people I know but it is curious. The fact that certain species of octopus are made up of cells that are themselves individual one-celled animals is amazing.