Forget IQ for a moment, for all the good reasons that other people have given you.
One of you will know more than the other or learn more easily than the other. That’s unavoidable. Even if the gap seems small, there might be key moments where the gap causes conflict. This is going to happen, whether it’s you or them who “is ahead”.
The question is this: how do you handle it?
If you treat each other with contempt, that’s a problem. That could be you assuming that they are always going to look down or you or them assuming that you’re not trying to “be better”. There are many ways for this kind do contempt to show itself in your relationship. Each of you has the responsibility to not think that way. Each of you has the responsibility for accepting and loving the other.
If you can’t learn to do that, then your relationship is doomed to fail. If you can learn to do that, then you stand a chance.
You both can choose.
Some things about my partner used to irritate me and I learned to accept them for the things they’ve tried to change but just can’t. That acceptance is key.
Good luck and peace.
What’s normal is that you had a traumatic experience, then internalized a Survival Rule to avoid repeating the behavior that led to the trauma. Depending on your age when the original incident happened, the Survival Rule might sit very deep, causing you to follow it even without thinking and without knowing why.
All that is normal: expected, sensible, reasonable.
The rule itself might no longer be needed. Can you imagine a situation in which it would be perfectly fine to interpret as a joke something that someone says without specifying it as a joke? Can you imagine three? Ten?