Postcode pride/envy

Hey guys, a quick story and a question. Ten years ago I was living in Abbotsford on Great North Road, near the roundabout that marks the entrance to the suburb. At a local social gathering one day, I was having this pleasant conversation with a nice lady from the “neighbourhood” (or so I thought) up until the time where she asked me exactly where I was living, to which I replied Abbotsford, obviously, then she said yeah of course but where exactly? So I pointed to great north road, mentioning the proximity to the IGA… to which she just snapped back “well no, dear, that’s Wareemba” on the tone that was like she’s telling me where I actually live, mixed with “don’t make that mistake again, you silly” kinda vibe.. after which the conversation just died out.. lol. That just got my mind racing, like I was feeling like snapping back “bitch I live in Abbotsford, both by postcode and map border, wtf are you on about? If my house was actually in Wareemba, I would say I live in Wareemba, like I don’t need to have misplaced snobbishness.. seriously” but obviously that would have been futile, and only made more of a fool of myself.. So basically I had just lost a battle I didn’t even know I was in, and there was nothing I could do about it! Very puzzling, and as you can see, I still think about that sometimes.. haha. But anyway so today that got me curious to ask you folks: is there other pairs of neighbouring suburbs in Sydney, one posh and the other “normal” that have that unhealthy toxic dynamic of such strong postcode pride or envy (depending which side you’re in) because of an evident or perceived big “class gap”, so much so that the posh side’s residents proper, absolutely do not want to be associated with the “poor side”, and would not hesitate to go out of their way to put someone even from “the border” in their place, kind of thing? Just curious, as it’s not something you can really ask google lol. Thanks guys