As I’ve gotten older I’ve realized that a lot of very mainstream advice people get about dealing with careers, society, etc is like “don’t do XYZ* or you’ll be eaten alive out there.” Instead of like “don’t eat people alive out there.”
*XYZ is just normal human behavior.
She probably loves coke and can’t afford it in her budget to drink it so she’s lashing out. Hope you didn’t take it personally. It says more about her than you, who was just enjoying a cold beverage.