If you say, "I'm a Monkey," they immediately know you are either 24, 36, 48 or 60 years old. Asking a zodiac sign is a polite way of asking your age.
Si responden: "Soy Mono", sabrán inmediatamente que tienen 24, 36, 48 o 60 años. Preguntar el símbolo del zodiaco es una forma indirecta de preguntar la edad.