world famous ...ribs ,wings bbq ...etc etc......

As i am a  resident of south Florida its  a haven for all sorts of restaurants and establishments .....but i got to thinking...how does one get world famous with their  wings or ribs or such like....

When a restaurant declares .....".Bubba's world famous hamburger "  i mean the world is a big ,big place ...

.does this  mean if  i was  on an expedition say in the amazonian basin....and suddenly descended on a tribe of plate lipped cannibalistic tribesman....and they were going to kill me ...should i say hey  have you tried bubba's world famous burgers ,i would expect they should know what i am talking about.....

Or say i was  with a  friend in the Serengeti at dusk and we met  a couple of African guys sitting around a  camp fire ....and walked up to them...and said ...."hey have you been to salty sallies seaside tavern and tried her clams"..they are world famous you know......

What constitutes world famous is it because a couple of beer drinking Brits on a vacation on a cruise ship stop in to say fort lauderdale or Miami and  get hammered and try  bubbas burgers and go back on the cruise ship to London....

Then they get back to the pub in London...All right mate we went on a bloody cruise got hammered and had these  bloody burgers at some geezer called bubba,s...........

It all seems strange that world famous ,is there a  committee that comes to a place of cuisine and says yes we have heard the someone in Tanzania heard of your oysters....or clams.....

Or is it a self proclaimed thing that when a  bar/restaurant opens up its put there  to make it sound like its been there for ever......

How does one's food get famous and how far across the global spectrum does it have to be mentioned to be world famous!!!!!!