I've always felt challenged when attempting to keep my small talk small by a part of me that doesn't enjoy the "good, you?" and "fine, yourself?" conventions. I find myself wrestling with a twirling, maddening, urge to say something else entirely. I'm not sure to what extent my experience with this overthinking of small interactions is shared by others, but my guess is that it's a common thing uncommonly expressed (except perhaps here, in the safety of the net).
A typical strategy I find myself using when confronted by an unexpected small conversation is to say the first thing that pops into my head, which is typically supremely silly. The other day it was "Oh, you know, same as usual, just fighting crime in a dangerous city." Another day it was "The work never ends, I'm like a cat on an infinite waterslide."
What's interesting here is that I'm not sure whether I am being more or less authentic than the person who responds to a shallow platitude with just another shallow platitude. Am I more, or less, distant from my speaking partner when I make a joke instead? I'm not sure.
What I can say for sure is that the sheer abundance of shallow interactions navigated in the span of a single day makes me crave the deeper ones. The ones that twist into dark tunnels under the surface until they suddenly pop back out into the light, like whitewater rapids. But those come around so much less frequently, and must be spent wisely -- which is perhaps why sometimes, I find myself attempting to convert shallows into deeps.