Walk down the street, run into some young kids toting some consumer good around on bikes during school hours because they can't afford not to, and they'll ask, “How are you?”
Surprised at their English skills, and perhaps having recently been caught in a deluge, you'll answer, “Oh! Ahh...I'm a little wet.” To give evidence, you'll indicate your pants, which are soaked up to mid-calf. “But all right. How are you?”
“Fine,” they'll say.
There was, you should know, never any doubt.
In fact, it's very likely they didn't understand your answer. It's likely, after answering, they will ask again.
“How are you?”
You may be confused, having already answered. However, you won't want to seem rude, so you'll laugh and say, “Yeah. Yeah, I'm all right. Not bad.”
This, however, is not good enough for them. They desire more for you.
“Fine?” they will helpfully suggest.
“Umm...yeah,” You'll realize. “Yeah, I'm fine!”
A smile will break out on their face, and they'll happily go on their way.
And you'll also smile, knowing that, all in all, you're just fine.