It probably says something about us that we address people by "coach" and "doctor" with equal solemnity.
Like, if I met Jim Tressel on the street as he was halfway through horking down a hot dog while wearing a windbreaker and white sneakers, I'd have to pause for a hot second as I mentally cycle through which honorific to address him by.
I'd probably settle on "coach," despite the guy being a president of a college and being of equal education to myself (we both have our M.Ed's), which is basically my tacit acknowledgement that him winning a national championship trumps my own ability in literally any other topic or scenario.