1. My brother can be so thickheaded sometimes, refusing to listen to reason.
2. Despite all the evidence presented to him, he remained thickheaded and stuck in his beliefs.
3. She was too thickheaded to realize she was being taken advantage of.
4. His thickheaded attitude caused him to miss out on a great opportunity.
5. The thickheaded student refused to ask for help, even though he was struggling with the material.
6. I can't believe how thickheaded she is, always making the same mistakes.
7. His thickheadedness prevented him from seeing the consequences of his actions.
8. The boss was frustrated with his employee's thickheaded behavior.
9. It's hard to have a conversation with someone who is so thickheaded and closed-minded.
10. Despite being presented with all the facts, he remained thickheaded and refused to change his stance.