This book is as inescapably English as… fish and chips, or bangers and mash, or tea and crumpets, or [insert your own favorite quintessentially English foodstuff]. The similarities come up in the little things: Christopher watches David Attenborough on TV (149.60), his mother reads a biography of Princess Diana (233.112), and his father insists on staying home on a Saturday to watch a football (as in, soccer) match between England and Romania (67.1). However, we can assume Christopher has no sense of being English, and no connection to his fellow Englishmen in general.
This puts him in an interesting position of presenting an accurate picture of life in his home country, while also being completely unaware that English culture might in any way be unique. Surely he would notice, if he went somewhere else, that things there were different, and he would probably call those things "weird" and have a difficult time with them. That said, he does recall having once been to France, but only mentions their speaking a different language (67.4). His conclusion from that experience is to come away simply "Hating France" (73.2). And, really, what's more English than that?
Back to the details, though. The first half of the book takes place within a remarkably small area – what Christopher himself describes as "home, or school, or the bus, or the shop, or the street" (181.2). These are the places where he feels comfortable, because, as he claims, "I have seen almost everything in it beforehand and all I have to do is to look at the things that have changed or moved" (181.2). Christopher's familiarity with these places comes through in his writing – his familiarity is somehow contagious, and even without much by way of detailed description, we feel like we know them ourselves.
As he moves outward in concentric circles of unfamiliarity, he draws us diagrams of these new places. While these new maps supposedly help us know these places better (for example, the layout of his neighborhood), they also really heighten what uncharted territories they are.
In the second half of the book, when Christopher tries to step outside of this familiar space, he's completely overwhelmed by the unfamiliar things: not only their number, but their size and intensity. And the way he describes things is accordingly wrapped in a mixed-up confusion. The diagrams get more and more complicated (for example, the train station) and then devolve into lists of postal codes, like "London NW2 5NG" (211.40), and subway stops (211.54).