What’s *much younger*?
Much younger than 30 can be 20. You’re not also going to jump on the *Well, twelve is maybe physically mature, so what’s the problem* bandwagon, are you? Because there’s a big difference in mental and emotional and yes, physical maturity of the human body between 12 and 13 and even 15, much less 16-18.
Please tell us what age you’re referring to and show us your statistics to back up age range.