Yes when I first moved to the US, people would greet me with "How ya doing?" and I thought they really did want to know. It took a while to understand that it was just a way of saying hello.

I'm told that, in China, a way to greet someone is to say: "Have you eaten yet?" 你吃了吗

You are not supposed to provide a detailed answer such as: "Yes I ate a breakfast sandwich this morning at 8 am".

Instead you simply say "I ate" (吃了) or "Nope" (没呢)