propellerhead

An old-fashioned name for a nerd, it is a symbol often linked with geek culture and tech-savvy individuals to refer to someone very knowledgeable about computers.

Historical perspective: In 1948, Artist Guy Pène du Bois painted a “Boy with a propeller beanie” hovering up in the air above a sandy beach. It was later popularized in a puppet television program called "Time For Beany." The propeller hat then became popular with nerds because of its association with the cartoon character Beany from the TV show "Beany and Cecil." 

In the 21st century, propeller beanies are rarely seen and are usually worn for comedic purposes. Google used to offer these to their newly hired employees, Nooglers, as part of their onboarding.