I have never celebrated Halloween, and the whole business is a mystery to me.Nor I. It's not a Chinese thing (we have 中元节 (zhōngyuánjié) or Hungry Ghost Festival (http://en.wikipedia.org/wiki/Ghost_Festival)), and Australia doesn't get nearly as excited about Halloween as the USA. There is plenty of tacky cloned-from-USA-pop-culture stuff in the shops though.
Q: How do you someone is a Pagan?
A: They'll tell you when you drive past a church.