You can change the controls, such as maybe you don't want them to play anything rated T or higher, but then your child gets older, you can go back and change it to allow maybe all T rated games, or have no restriction. Same for movies being played on the
system. What you can't do, however, is change the account to an adult account or change the birthday. You can turn it into an adult game account once the child turns 18 according to the DOB you entered when you created the account.
Is that what you were asking? Does that help? Just let me know, and I'll be happy to help.