The original inspiration for this phrase is believed to be ex-professor Radim Servít of the Faculty of Civil Engineering of the Czech Technical University in Prague (CTU).
He taught elasticity and strength of materials in the 1960s and was infamous for his extensive rigour in exams.
[2] Students started writing the words Servít je vůl on the walls of public restrooms in bars nearby the CTU campus.
Thanks to the political mood in the 1960s Czechoslovak Socialist Republic, this graffiti has gradually spread out of Prague, the country and Europe through students and their voices.
Some of the confirmed locations where this graffiti has been found include: As time progressed, various new versions of the phrase were created, for example: Doopravdy nejsem vůl, Servít (I'm really not an asshole, Servít), Všichni jste volové!