One learns to function in a world of posters, postings, signs, ads, ordinances, notices and indications of “material culture” (i.e. commerce expressed in designs and slogans on walls and buses, subway cars, etc.).
Think of the 1963 movie The Great Escape. There’s a scene where James Coburn’s Australian character is sitting in an outdoor cafe on the French/Spanish border and the waiter comes over to him and pulls him toward the counter and says, “Telephon, monsieur.”
The James Coburn character has no idea why this is happening but mimics the proprietor and son when they duck down. French Resistance fighters in a car gun down the Germans at the cafe and James Coburn’s character “gets it” and asks them for help to get into Spain. As he ducks down you see posted on the wall of the cafe several ad signs for drinks. One of them is “Byrrh”:
“Byrrh is an aromatised wine-based apéritif made of red wine, mistelle, and quinine. Created in 1866 and a trademark since 1873, it was popular as a French apéritif. With its marketing and reputation as a ‘hygienic drink,’ Byrrh sold well in the early 20th century.” (from Wikipedia)
In many French movies or movies set in France, such as Belle de Jour and The Legend of the Holy Drinker from 1988 (in which a drunken homeless man [played by Rutger Hauer] in Paris is lent 200 francs by a stranger as long as he promises to repay it to a local church when he can afford to; the film depicts the man’s constant frustrations as he attempts to do so).
Set in Paris, the ad notice “Byrrh” appears in the same way you’d expect to see “Coca-Cola” and know what the sign signifies. “Coke” is a drink and not the fuel coke. How exactly you make these distinctions is unclear to linguists and other language-watchers. It’s a social phenomenon, partly, like mores and manners.
In the movie The Book Thief (a 2013 World War II war drama, starring Geoffrey Rush, Emily Watson, and Sophie Nélisse, based on the 2005 novel) there’s a moment when you see a sign advertising or reminding you of “Kolonialwaren” (i.e., colonial wares) which was the German way of pointing to a place or store that sold coffee, tea, cocoa, etc. Any German adult of the period would know what “Kolonialwaren” signifies without quite knowing how he or she knows.
A traffic sign (you have to of course realize it’s a traffic sign and not some commercial ad) tells you “Boston 20 m.” You realize or guess it means 20 miles and not 20 meters (since meters are not a typical American measure) nor would it be 20 minutes since that would assume everyone is driving at a speed that gives you 20 minutes, which is far-fetched.
How a person goes from birth to adulthood whereby they spontaneously navigate a welter of different signs and postings, ads and statutes is quite opaque.
Roland Barthes (died 1980) explored this domain of signs (not only physical signs but mythology as a system of signs) all his life:
Barthes is one of the leading theorists of semiotics, the study of signs. A sign, in this context, refers to something which conveys meaning – for example, a written or spoken word, a symbol or a myth.