There’s a joke that goes like this: John is a software programmer. His wife Alison asks him to go to the store to pick up some groceries. "Hey John, get two bottles of milk please," Alison calls out as John is getting into the car, " and if they’ve got eggs, get a dozen." The programmer returns with twelve bottles of milk.
Sometimes what you hear is what the customer said, but not what the customer meant. It’s always useful to clarify, consider the alternative meanings, and make sure you’re returning with what the customer needs – which is not necessarily what she asked for.