Now what should I say/react when people (aka strangers) smile at me?

Oh wait. People don't in Singapore.

It doesn't matter. (Sometimes) I don't smile at them either, why should they do so to me?

That's the difference. Between north and south, mature and immature, developed and developing...crapping trails off...

The lady whom I bought my clips from (in Penang) recognised me when I passed by her in the market on Monday. We smiled at each other. I wonder, would that happen here?

Ah. Then again, it doesn't matter. What matters more is how I perceive those people (aka strangers) in Singapore now. ;)