If somebody looks at you and sees little difference in the way you present yourself between you and somebody 10years younger, it probably is true that there little difference in maturity.
Look at people in general by age group who are into baggy clothes, most of the younger ones(and older but not so mature ones) would sag and the older seemingly more mature would keep it baggy but not sag. and if it matters to you what age group you date, like it or not, if you sag, you stay dating broke immature women or students. the age group you date will stay the same as you get older.