It is all relative. For eg. if you have all the while been driving to work, and suddenly you have to take public transport, you will feel the difference. I think it similarly applies when all the while you have been taking only MRT to work and suddenly have to switch to taking buses only.

The other issue is about empathy. Many of us are so caught up living our own lives that we forget to notice our less fortunate neighbors. It gets worse when there is tendency for the different income classes to congregate together. Most of us started off living in HDB, then when our income and wealth grow, we upgrade to condos or landed properties. So when you are living in a high end condo or landed estate, what you see and who you mix with daily are your similarly wealthy neighbors. And rich people tend not to take the public transport, so their exposure to the general public is even less.

You know what's worst? Many of the rich think everyone else is similarly rich, likewise for the poor, they also think that other people are the same as them - poor. So the net effect of this phenomenon is the poor would readily help a fellow neighbour, while the rich are less willing to do so, thinking that the guy can probably take care of himself.

A study in the US done on the incomes of rich and poor neighborhood noted this observation: that the rich tended to overestimate the income of the poor, while the poor tended to underestimate the income of the rich. The study also noted that many people whether rich or poor saw themselves as middleclass. The explanation given for this behavior was that people tended to stay in a neighborhood of similar income class. Rich people stay in richer neighborhood, see that they are similar to their neighbors and concluded that they must be average or middle class. Likewise for the poor.