Never have I met a woman so pigheaded!
Stubborn /ˈstʌbɚn/ 顽固的，固执的
He's very stubborn and it drives me mad sometimes.
Be as stubborn as a mule
I tried to convince Jake to go to the doctor, but he's as stubborn as a mule.
Set in one's ways 不愿改变
As he gets older he's becoming more set in his ways.
My boss is kind of inflexible and he does everything by the book.