Learning lessons is a little like reaching maturity. You're not suddenly more happy, wealthy, or powerful, but you understand the world around you better, and you're at peace with yourself. Learning life's lessons is not about making your life perfect, but about seeing life as it was meant to be.
The five stages - denial, anger, bargaining, depression, and acceptance - are a part of the framework that makes up our learning to live with the one we lost. They are tools to help us frame and identify what we may be feeling. But they are not stops on some linear timeline in grief.