Read the excerpt from "Song of Myself." Long enough have you dream’d contemptible dreams, Now I wash the gum from your eyes, You must habit yourself to the dazzle of the light and of every moment of your life. Long have you timidly waded holding a plank by the shore, Now I will you to be a bold swimmer, To jump off in the midst of the sea, rise again, nod to me, shout, and laughingly dash with your hair. What theme is suggested by this excerpt?