The philosophies presented in Huxley'sBrave New Worldare certainly different from many conservatives' thinking today. For example, "loss of innocence" today might mean learning about or experiencing something that changes a person so much that their life will never be the same. In the new world's case, however, becoming responsible for keeping the philosophy of the world in tact certainly makes it so that a Controller can't mingle with others. Therefore, Mustafa Mond is an example of one who has lost his innocence because he knows more than the average Joe and he cannot go back to that life ever again. In Mond's case, he gained more knowledge and responsibility, so he represented the epitome of having grown up. Others like Marx, Lenina and Helmholtz simply had to get up every day, work for a few hours and party it up the rest of the time. They weren't responsible for anything or anyone. Marx and Helmholtz do gain greater knowledge as they journey with John from his world to Mond's. The only difference is that Marx and Helmholtz don't become Controllers, therefore they don't gain any more responsibility. Their job from the end of the book is not to make trouble for those who are blindly living in their happy drug-indused state. So Lenina doesn't grow up, Marx and Helmholtz almost grow up, but Mond is the most grown up if using the above criteria to analyze maturity.