The great divide

I could not help but put this down after a recent conversation with some co-worker brought this subject back into my mind. He was saying that though he was staying at Worli, he would never drive his car through the Eastern Express highway, but always through the Western Express highway. It seemed he had a great contempt for the "central line". I could not understand the reasoning, but he had his ideas cemented. I wasn't asking him to stay in the central line suburbs - only travel along it, but he was unwilling (this is inspite of the fact that the Eastern Express travel is more faster than the Western Express).

This was not the first case of a virtual division of Mumbai - I have heard similar differentiation along different dimensions. Some of these lines for division:

City versus Suburbs
Though this is a bit outdated, it was quite prevalent until the 1990s. As per most people living in Mumbai between Colaba to Dadar, the "city" started at Colaba and ended at "Dadar". Anything beyond Dadar was a strict no-no and people thought that was the "city" limit. Of course, people staying in Mahim thought that the city ended at Mahim and that Bandra was the beginning of the suburbs. Their claim to fame was that the suburbs were physically divided from the city by the Mahim creek and the Mahim causeway was built to bridge the city to suburb gap. So, technically (and geographically), Mahim was very much part of the "city".

Recently (in the last decade or so), all that changed and most people now have a more positive outlook on the suburbs - with most celebrities shifting to Lokhandwala (near Andheri) and Juhu, the fortunes of the suburbs saw an upward trend.

East versus West
Another common division is "East versus West". Here, the division is on the basis of the railway line. Whatever is to the West of the suburban railway line is labelled "West" and similarly for the "East". Within a particular suburb, West would always find more buyers and higher real estate prices. Some exceptions exist especially Mira Road and beyond where the East is more developed (but then those are technically beyond Greater Mumbai city limits and in Thane district).
The fun part is considering places like Dadar where there are 2 suburban railway lines (Central and Western). In Dadar, the western part of the Central Railway is actually the easter part of the Western Railway. So, we hear terms like "Western Railway West" to specify things a bit unambiguosly.

Another tricky part is that the suburban railway line (Harbour line) curves beyond Juinagar and the right side of the direction of travel towards Panvel suddenly becomes the West (but here again, Juinagar is well beyond Greater Mumbai city limits and in Thane district).

Central versus Western
This is another division on the basis of proximity to the suburban railway line (Central versus Western). It is considered to be quite "nice" to stay in the Western suburbs and travel by the Western railway. I have known people who loathe travelling by the Central railway (as per public opinion, even the railway trains on the Central are more dirtier and smelly). Maybe this is due to the number of extremely long distance trains that the CR has to cover. For example, per day, there are almost twice the number of trains from Mumbai CST to Karjat and Kasara combined as compared to Churchgate to Virar.

Probably, it is human nature to divide and classify humans. Mumbai has given a different meaning to classification.