... second stanza, he says "I've built a wall, a fortress deepand mighty."He has built a mental block to all outsiders, and he comparesthis to aninpenetrable wall. Inpenetrable walls ... Hesaid that he doesn't want friendship because it just causes pain,and that thelaughter and loving he hates or despises. He wants to be leftalone, like itsays in the third stanza, "Hiding ... " ;a rock feels no pain,an island never cries."He wants to be like a rock, and like an island. Rocksdon't feel anypain, therefore, if he was a rock, he wouldn't feel any pain....