Do you ever get the feeling that being a well-rounded, cultured person who enjoys good insightful conversation about any topic sometimes intimidates others or turns them away?
Absolutely... and one possible reason is that you're reading them wrong. They don't want to be impressed with your brilliance...they want to be validated through you listening and showing that you get what they want and are willing to appease them.
If you're a $50 steak and the other person is a vegan what good are you?
This is going to be 10x so on a first date (or conversation) which are mostly about making her feel adored. That's really it. If she initiates an intellectual discussion, fine, but you don't. You're job is to inquire, listen, acknowledge, and react in a non-combative manner. If that person likes and is willing to not feel threatened by being challenged (which takes alot of trust and not typically happening on a first date) then you can pursue conversations about values and such.
(And of course none of this is a hard rule but it's my experience and I think it captures most common experiences.)