Reminds me of a movie adaptation of "A Brave New World" where everyone greets each other with "Hey how are you I'm great thank you".
By the time I had come up with some kind of answer they had already passed me by. I didn't realize I was supposed to answer by asking the same question from them, or some slight variation thereof.
I have a Peruvian friend who had a similar experience. He would relate that when you would ask someone in his country how they’re doing, it was expected that that would be the beginning of a (possibly brief, but probably not so brief) discussion.
I explained it means, essentially, what's up.
If you bumped into a pal and said 'sup and he then went on to explain his day at length that would be weird, right?
American and English, it's almost the same language.
Person C : "How's Person V doing?" Me : "Sadly he had to go back to India 'cos his Dad died" Person C: "Oh, cool, cool"
What the .... ? Person C clearly wasn't listening , I don't think he meant to be quite so uncaring.. maybe I wasn't meant to actually answer the question....