I am not a mustard person at all.
I can smell the day after someone eats it. I can smell mustard if the cook used it on another burger, then dressed my burger.
I don't like mayo/salad dressing-same reason-the smell.
My burger/sandwich will be dry, no mayo,mustard, pickles or tomato. Lettuce and onion only.
Once had BBQ, love it but not that time, 1 bite and no more. Not sure why but nope. Didn't go back either. Talked to someone that worked their months later and found out they rub Brisket down with mustard then sprinkle on the dry rub/seasonings before cooking. Guess that it what I was tasting. To each his own. Love pickles-just not on burgers/Sammies.