I have only one complaint about this fantastic story, and it is this: the library is claimed to be infinite, and to contain all possible books it is possible to ever print, each distinct from any other. But for a given alphabet with finite symbols, printed on books of uniform and finite dimensions, using typefaces of uniform and non-negligible size (to facilitate reading, duh), fit onto bookshelves of standard and finite size, there can exist only an finite, and indeed enumerable number of unique books. The number would be big, mind-bogglingly big, but nowhere near infinite. But perhaps the narrator did hedge against this fallacy of the infinite by speculating about whether the library wrapped around itself, so as to give the impression of limitlessness, when its explorers are just wandering around in endless circles.
That is all.