I agree with ISPIRIKITIK...so many reasons why it happens..work is a very big factor, i must say..

as for me, I don't smile to every Filipino in the road or anywhere..but if you smile at me..of course, I will answered back with a smile..

stanley mnl, just make your circle of friends and enjoy..i'm sure you won't anymore bother not to be greeted in the stree because you are now too busy going out with friends...:)

just my 2 cents. :)