A person who is
headstrong but
to the point where theyre foolishly or irrationally stubborn; obstinately
opinionated, especially in refusing to consider alternatives.
Basically theyre hard to work with because he/she believes they have all the answers, regardless of the facts or opinions.
Will is very bullheaded. He
literally shuns my ideas because he thinks he has all the
answers.
You are
the most bullheaded person I've ever known!