First-come, first-served. Kids learn this lesson at recess in grade school by sprinting to their favorite swing set before the other kids can reach it. There are rules, of course, to this classic social phenomenon; primarily, you can’t call dibs in your head. 

However, this entitled mom called dibs on the last box of specialty cookies at the grocery store, before ever setting foot in the bakery aisle, assuming whatever sorry sap stood in the way of her and her baked goods would yield to her craziness. Well, not this pregnant shopper, who was craving the cookies, got there first, and stood her ground on the rules of FCFS.