Responding to someone who claims to be older and more knowledgeable than you requires tact and diplomacy. Here's a polite response you could consider:
"I appreciate your experience and wisdom. I'm always eager to learn from others, and I believe there's something valuable to learn from everyone. Your insights and knowledge are valuable to me, and I'm open to listening and understanding your perspective."
This response acknowledges the person's claim without being confrontational and expresses a willingness to be receptive to their knowledge. It shows respect for their experience while also maintaining a sense of humility and willingness to learn. Remember, staying polite and respectful in such situations can lead to more positive interactions and discussions.