I found Branko Milanovic's "The Haves and the Have-Nots: A Brief and Idiosyncratic History of Global Inequality" to be an eye-opener. Roughly paraphrased, if you're in the top half of the US, your equivalent in India would be the top 1%.

I don't remember if it was that book or something similar I read around the same time, but I have a faint memory of membership in the Indian middle class essentially being "owns a household appliance".