Not too bad

What do you say when someone says "How are you?" to you? When you you are doing alright?

Today, I answered my mobile, and said "Not too bad" when a colleague asked me "How are you?"

His reaction was comical. He kind of laughed for not knowing how to react to my answer! As if it was the last thing that he had expected to hear from me!! I've been working for the company in Mumbai for nearly a year, and I must have been saying "Fine" until today.

Recently, it annoys me to hear people answering "I'm good", "Great", "Good",etc. Mostly from Americans, but it seems that such a way of replying to "How are you?" seems  becoming more and more common. As far as I remember, all my Indian colleagues answered in that manner, too. It just sounds so artificial to my ear, and makes me want to ask "Really?" Actually, I asked "Really?" when I asked how this person felt becoming 40 and his reply was "Great". (There was another man beside us, and he was laughing his head off.)

Come to think of it, I always say "Not too bad" or "Doing alright" when people in this town ask me "How are you?" "How abou' ye?" etc. And it's not a strange expression to their ears. Must be something regional.