Mature-minded is subjective; however if you are mature enough then you can earn your freedom. A naive person who earns their freedom with birthrights doesn't really know what freedom is, and if you are born into it then you are actually enslaved into freedom, rather than earning your freedom. This could also be subjective.
Aside from the fact this notion itself is ridiculous it begs the question of defining a 'mature' minded person (a definition I do not doubt would be non-subjective and relative) and what it means to be 'free' in whatever sense this question is referring to. It's difficult to confidently assume what this question is supposed to even mean.
At what age would you consider someone mature minded?
At what IQ are you mature minded?
How would you distinguish who's sophisticated and who's inane?
How could you conclude ANYONE was mature minded having never experienced freedom?
Education's lineage derives from experience; being oppressed throughout life resolute's you with nothing.