clients call me "sir" on calls and i'm internally like... bro i'm 21 :)

started a small agency back in undergrad, now doing my masters at masters union and still running it from hostel room. every client call, they're super formal. "yes sir" "thank you sir" and i'm like... bro i'm a kid 😭 but obviously i don't say that. yesterday on a call, guy asked me some technical question about pixel tracking. i BLANKED. fully sweating, heart pounding, somehow fumbled through an answer. he just goes "perfect, exactly what we need" and i'm sitting there like... does he know i ...