Threadstarter,
It is possible that by virtue of your "lucky" background, people
get jealous and make comments about you, including the so-called
close friends.
You mentioned that you do not like to show off, and that wearing
designer labels and driving a "normal" car is no big deal.
I agree with you, but...
...you may have overlooked the fact that owning a car without
having to save and pay for it already makes people jealous.
I don't know enough to say that your behaviour is off-putting to
others, but perhaps nobody can really see their own faults, can't
they?
And in materialistic Singapore, people do get jealous. Even
siblings can get jealous over one another, let alone friends.
The best way to entertain that cohort of jealous friends is to
leave them alone, and not mix with them much.