Comment by antonvs

> is there any nesting in there at all? I can't see any.

There's an enormous amount of nesting in there. However:

1. You probably aren't familiar with the linguistic definition of the term - see e.g. https://www.lancaster.ac.uk/fass/projects/stylistics/topic7/... for a summary

2. Your brain deals with it without you recognizing it

3. Hemingway often avoids punctuation to give the illusion of an un-nested stream.

Here's a version with some of the nesting annotated, just to give an idea of how nested it is. It may look excessive, but in fact it's missing some nesting because I don't have infinite time:

"[He was an old man [who fished alone [in a skiff [in the Gulf Stream]]] and [he had gone eighty-four days now [without taking a fish]].] [In the first forty days [a boy had been with him.]] [But [after forty days [without a fish]] [the boy's parents had told him [that [the old man was now definitely and finally salao, [which is [the worst form [of unlucky]]]]]] and [the boy had gone [at their orders] [in another boat [which caught three good fish [the first week]]]].] [It made the boy sad [to see [the old man come in [each day [with his skiff empty]]]] and [he always went down [to help him carry [either [the coiled lines] or [the gaff and harpoon and [the sail [that was furled [around the mast]]]]]]].] [The sail was patched [with flour sacks] and, [furled], [it looked [like [the flag [of permanent defeat]]]].]"

As an example of missing nesting, "[In the first forty days [a boy had been with him.]]" should be more like "[In [the first forty days]], [a boy] [had been [with him]]."