I think it's discriminating to pose a specific age as a maturity goal reached. There is so much divorce and broken marriages nowadays that it's not "one age group over another." It's everybody.
My wife of 10 days is 24 years old. She is by far the most mature and independant person I've ever met. She had about 3 or 4 boyfriends before she met me. So according to your statement, she can't possibly be more mature and have experienced enough in the dating field to have gotten married to me?
I dealt with all my "bad eggs" around 21-22. My age was only a number and nothing more. I was never the partying-immature-college type person. While I agree that many people need experience to know what they want (hence my "love at first sight is impossible" theory), age is really and truly only a number.
And also, I lost my debate about divorce being an abomination. So basically, the message sent from that loss was "Free for all." Get married, get divorced, have children, desert them. Who cares, right?"
Just like the very thing that everyone seemed to throw my way about "You can't MEASURE love's limits." You also can't measure who's old enough, mature enough, experienced enough, to get married.