Is the last paragraph just a poetic ending or a demonstration of wandering mind affected by dementia? The sentence can be parsed and seems to have a discernable meaning but the associative leaps and comparisons seem highly unusual to me.
I honestly can't tell. Perhaps because I'm a non-native English speaker with a lack of subtlety when it comes to literature.
It's a bit purple, but it reads fairly cogently to me; it's just a very long run-on sentence.
That might be attributable to dementia, or a deliberate style choice; I'd kind of lean towards the latter given that plenty of the preceding article is expressed in clipped, curt statements without much excessive detail.
It is sad, though. The writing of Terry Pratchett puts this on somewhat depressing display, with many of his later novels lacking the punchy dialogue and tight focus of his early and mid-career works. They feel a bit more floaty, out-of-focus, and characters are more likely to pontificate than demonstrate a point through action or indirect reference.
They're still good stories written by a very talented and creative author, but you can tell that he was having more difficulty with it towards the end.
Similar to Pratchett's later books -- and Iris Murdoch, as mentioned in another comment -- are the late works of the composer Iannis Xenakis. As long as a decade before he was forced to withdraw from public due to dementia, his music underwent a very peculiar stylistic change where the immense complexity of the earlier pieces (Xenakis built his career on combining music with his work as a modernist architect and erstwhile student of maths) gave way to a very repetitive, single-minded sort of texture.
I think its an allegory. The cycle of seasons, of leaves hiding their brilliance within an overbearing green, finally revealed at the end but clinging on to life by a small thread, to be blown away to become worm-food, and the life force from which the next generation is born.
You managed to get through the first three or four paragraphs unscathed and got to the end and then manage to come up with a comment that is extremely cogent.
In a second language.
The final paragraph is probably just as intelligible to you as it is to me - it says things that are just a little bit beyond mere language. The words and phrases have meaning but the sense that is conveyed is way more than the symbols themselves.
Purple prose? - fair one; but I think that, given the preamble, we get a sense of sheer and utter sense of potential loss, combined with a tenacious desire to be.
"it says things that are just a little bit beyond mere language. The words and phrases have meaning but the sense that is conveyed is way more than the symbols themselves."
This describes how I feel reading a lot of Cormac McCarthy's writing.
I honestly can't tell. Perhaps because I'm a non-native English speaker with a lack of subtlety when it comes to literature.