In single sentence.
Quote:That something I cannot yet define completely but the feeling comes when you write well and truly of something and know impersonally you have written in that way and those who are paid to read it and report on it do not like the subject so they all say it is a fake, yet you know its value absolutely; or when you do something which people do not consider a serious occupation and yet you know, truly, that it is important and has always been as important as all the things that are in fashion, and when, on the sea, you are alone with it and know that this Gulf Stream you are living with, knowing, learning about, and loving, has moved, as it moves, since before man and that it has gone by the shoreline of that long, beautiful, unhappy island since before Columbus sighted it and that the things you find out about it, and those that have always lived in it are permanent and of value because that stream, will flow, as it has flowed, after the Indians, after the Spaniards, after the British, after the Americans and after all the Cubans and all the systems of governments, the richness, the poverty, the martyrdom, the sacrifice and the venality and the cruelty are all gone as the high-piled scow of garbage, bright-colored, white-flecked, ill-smelling, now tilted on its side, spills off its load into the blue water, turning it pale green to a depth of four or five fathoms as the load spreads across the surface, the sinkable parts going down and the flotsam of palm fronds, corks, bottles, and used electric light globes, seasoned with the occasional condom or a deep floating corset, the torn leaves of a student’s exercise book, a well-inflated dog, the occasional rat, the no-longer-distinguished cat; well shepherded by the boats of garbage pickers who pluck their prizes with long poles, as interested, as intelligent, and as accurate as historians; they have the viewpoint; the stream, with no visible flow, takes five loads of this a day when things are going well in La Habana and in the ten miles along the coast it is clear and blue and unimpressed as it was ever before the tug hauled out the scow; and the palm fronds of our victories, the worn light bulbs of our discoveries and the empty condoms of our great loves float with no significance against one single, lasting thing – the stream.
That's how Ernest Hemingway described Gulf stream in his 1935 book "Green Hills of Africa".