"More thickskulled" is a term often used to describe someone who is obstinate or refuses to change their ways. Some other synonyms for this term include "stubborn," "close-minded," "unyielding," "dense," "obdurate," "polarized," "resistant," "uncompromising," and "hardheaded." These words all describe someone who is difficult to convince or persuade because they are set in their ways. While it can be frustrating to deal with someone described in these terms, it is important to remember that everyone has their own perspective and reasons for their beliefs. It may require patience and empathy to provide a different perspective and potentially change their views.