On its origin, Uncle Hanzi says:fán) has little to do with a sail, but there is a similarly-looking 帆 which is also pronounced as fán and means “a sail” or “a sailboat”. 虫 (chóng) means “insect”. According to Wiktionary, “Ancient Chinese thought insects appear with wind”. So far so good, but then it goes, “Insects refer to any kind of animal, such as tigers”. Maybe not too straightforward way to memorise it for a modern learner. Forget the insects: you still can think of 风 as depicting a sail, a flag, or, as Tamara has suggested, a curtain moving with the wind.