This salutation is irksome for being, if nothing else, vague. The listener can interpret the question in any number of ways and all the responses are correct and understandable except one, to wit, “How am I doing what?”.
This reply is usually met with a repetition of greeting with the accent either on “you” (“How are you doing?”) or “doing” (“How are you doing?”). I respond in kind: “How am I doing what?”. It is at this point that I know if I have engaged a human being or an automaton.
The longer the time that an individual takes to understand what they are saying, in contrast to what they believe they are saying, is a rough estimate of their intelligence and awareness (not unlike “What’s your sign?”) This length of understanding can be measured in seconds, minutes or, for less fortunate individuals, the number of encounters.
Doubly annoying is the not uncommon variation of “How are you doing today?”, where I respond “How am I doing WHAT today?”
Any doing on my part must have a purpose and there are many possible enquires, such as-
“How am I doing taking over the world?”
“How am I doing corrupting the youth and denying the gods?”
“How am I doing sacrificing small woodland creature for my financial improvement?”
-that can be answered quickly and thoughtfully, although in the last example, truthful should, in my experience, be avoided.
Gentle Reader, I hope this writing will assist in future encounters of the mindless kind. And since the cashier is bewildered and confused during this time, the coup de grass is when he asks “Is that for here or to go?” and you respond cheerfully
“Yes!”.