At the ceremony, the child was presented with a bracelet of knowledge/maturity, which was a sign of accountability and responsibility towards fellow citizens and Yahvo. The individual was now expected to have true knowledge of good and evil and the wisdom to make the right choices. Associated with the bracelet were certain rights as well as expectations to behave in a more correct manner.
On a religous level, Yahvo now expected more from them. Parents were no more judged for the actions of their children on a religous level, and lack of knowledge is not considered an excuse to Yahvo.