It was a surprise to me to really understand that text files don't consist of lines anywhere, they are byte arrays. Interpreting
97 98 99 13 97 98 99
as text with lines
abc
abc
is just one way to view it, but only 'correct' as far as saying agrees with the author's intent, but not objectively 'more correct'.
I now think that being able to interpret the same thing in many ways, and shift between them at will to use the most useful one or leverage a different tool, is a key skill in computing and programming which doesn't get discussed all that often. Vim uses it in letting you treat it as lines, words, sentences, paragraphs, blocks, screens. Regexes let you treat it as character sequences, arbitrary sequences of patterns, repeating patterns. Hex editors go for the byte level. Structure editors let you treat it as INI blocks, key=value pairs, XML trees. IDEs let you treat it as functions, methods, classes, headers.
And the more of them you can see, the more tools you can use - e.g. treating CSVs as lines of text in one context, then comma separated text, then comma separated dates and numbers and text, then entries in a user database, that lets you do different kind of processing on the same data where someone who sees it only as "a CSV" is more restricted.
(I suspect that's a part of general thinking; being able to see the same thing in different overlapping contexts which let you take it apart at different size boundaries; e.g. a dessert on a table, is also a trifle, which is part sponge cake, which is a flour/butter/egg/sugar mix which is a starch/fat/binding/sweetner and that lets you rebuild it either as swapping the trifle out at your dinner party, or swapping the sponge out for biscuits in the trifle, or swapping the butter for margarine in the sponge recipe. Someone stuck in the pattern "children's parties always have trifle" or "this is an Italian theme dinner party so it has to have an Italian dessert" is limited, someone who sees a trifle as something you buy from a shop and can't make one, is limited, someone who sees trifle as "made with sponge" is limited, someone who sees sponge as a single recipe is limited, someone who can swap any part at any level at their convenience is more flexible, less limited; someone who can do that on the fly for any of the foods on the table, would make a really good cook/host/organizer).
See also: inside computers, it's all bytes, that's all there is.
See also: Steve Yegge classic essay "The Emacs Problem" https://sites.google.com/site/steveyegge2/the-emacs-problem "How did I get so far off the original track of text processing? Well, that's the punch line of this shaggy-dog story: it's all text processing! Log files, configuration files, XML data, query strings, mini-languages, programming languages, transformers, web pages, word documents, everything... the vast majority of your programming work involves text processing somehow. What would you rather do? Learn 16 different languages and frameworks in order to do "simple" log-file and configuration-file processing? Or just buckle down, learn Lisp, and have all of these problems go away forever?"