Watching my DD's swimming lesson, I finally realised that no one ever needs to be able to swim bufferfly. Breaststroke is good for ploughing up and down, front crawl is good for going faster and back crawl is lovely and chilled, each has a role. But butterfly is there just to be awkward. I've only ever seen one adult swim butterfly at a public pool and they were so slow they might as well have been going backwards. Why do children still dutifully learn butterfly?