Max von Sydow named after a Flea

In a recent interview the actor Max von Sydow comments that he was named after a flea. The swedish actor appeared in Conan the Barbarian, perfored for Bergman in The Seventh Seal, won an oscar for Pelle the Conqueror and more recently appeared in Minority Report and Rush Hour 3.
Max was origionally named Carl Adolf after his grandparents but in the 1940s the name became less popular. During swedish national service he performed for his comrades in an imaginary flea circus. And the star of that circus was a flea called Max. Following this the colonel of regiment started calling him Max and the name stuck.