Not all such problems can be traced to maturity. Some people just don't do well in environments when your behavior is controlled. Just because people learn to deal with it eventually doesn't mean it's related to maturity. Some people are born into a cubicle, others prefer less structured environments and continually fail at traditional jobs until that happens. Independence is incredibly valuable and I don't fault him at all for needing it more than the rest of society.
EDIT: And I really hope you wouldn't say this to his face, I hope you understand what you're doing. Calling him immature only makes his problems worse, he came to HN for help and got criticized unfairly.
EDIT: And I really hope you wouldn't say this to his face, I hope you understand what you're doing. Calling him immature only makes his problems worse, he came to HN for help and got criticized unfairly.