I look at it as a teaching experience.
Yes, I've had the Hollywood-induced question: "9MM, huh?" Since I have several options I could be carrying, it could be a .22LR, 9MM, .40S&W, .357SIG or .45Auto.
When I respond with: "No, I prefer the .357SIG for this application" - I usually get the deer-in-the-headlights look. Several folks still don't understand that there is a difference between .357MAG and .357SIG.
I have carried a concealed weapon for years and occasionally someone 'discovers' that fact. I'm most annoyed that I've been found out, but fortunately most are people I know and they are simply curious as to what I'm carrying. On the rare occasion that I show the weapon, most ask: "That looks like a Glock". To which I respond: "Well, no, that is a SIG". "That a 9MM?" "No, that's a .45" "Damn! a .45!? Do they still make those? I thought they went out in WWII"
More opportunity for another teaching moment.