Excuse Me Sir, But You’re A Sir Too

I was going for the whole Ben Harper thing but I’m not sure it worked. At any rate, allow me to share a story of an awkward greeting that happens to me quite frequently. I understand that in the military it is quite common to address many people you don’t know as sir. I’m down with that. What makes me feel uncomfortable is when I pass older gentlemen in Petworth and they say “Good morning sir” or “How are you, sir” to me. I just don’t feel a “young” kid like me is deserving of the honorific. I always think to myself, why are they addressing me as sir? If anyone should be addressed as sir it is they! So what is going on here, is this a generational thing? Should I respond back using sir as well?