A: Did you pick up your vitamins at the health food store?
B: I tried but there was a 'Birkenstocker' following me down every aisle and I had to ditch him.
A left wing alternative to redpilled, and a reference to the Barbie movie when Barbie is offered a Birkenstock and a high heel, and the Birkenstock represents the truth
Old hippies who break all rules of class and taste by wearing wool socks with their Birkenstock (or Birkenstock-rip-off) sandals. A serious fashion faux-pas.