When McMurphy first showed up to the ward, he was a conman. He didn't care about anyone but himself.  His first days in the ward were spent taking advantage of the patients and insulting them.  However, as time went on, he got to know and like the other patients.  He suddenly cared about them and wanted them to stand up for themselves against Nurse Ratched.  He led their battle against her to earn some basic rights and privileges that any grown man deserves, such as the right to smoke or watch tv when they want to.  He was determined to teach these men how to live again by taking them on a fishing trip and giving them a taste of freedom again.  His actions show he changed from being a self-centered troublemaker to a caring leader of the oppressed.