It is generally regarded by most people that women mature faster than men do. There are a lot of reasons for this, but the one that needs to be addressed here is what actually matures a person.
Maturity is the recognition of responsibility and then the acceptance of that responsibility as a necessity in one's own life. A woman typically comes to this realization faster than a man does. Often a man sees responsibility as an enemy, something that just gets in his way of living and having fun.