Unknowingly we have actually made the goal of our life sorrow. Our desires normally stem from objects that will not give us eternal happiness. We know it can't be eternal because if it has a beginning, and so it has to have an end. That end is the birth of sorrow. Swamini Supriyananda explains this thoroughly, through a beautiful humorous story. To connect with joy, we have to disconnect with sorrow, and disconnect with our attachment.