A thicket is often used as a metaphor for a place so dense that it hides things from view. In line 8, however, the poet makes reference to a "thicket of nowhere left to hide", downplaying the importance of physical distraction, and placing emphasis on the meaning of the thicket itself. A person might not be able to see through the thicket, but one knows what is in it, and, in that sense, it hides nothing.
All It Takes