On an early date with my now wife she spent an entire subway ride to Queens telling me about Montessori education methods and how it made her the person she is. I recounted that when I was in first grade I was punished for interrupting the class by having a cardboard box put over by desk, so nobody could see me, and that that made me the person I am.
So two passing tests in one convo: she was impressively interested in things that matter (I was already infatuated with her) and she was not put off by my bullshit.
This is one of the most pithy bits of marital advice I’ve ever read, but easier said than done! Emotional maturity seems to exhibit a very pronounced Dunning-Kruger effect. Also, people continue to mature emotionally in adulthood and this can occur at very different rates.
Just as a vivid example, recovery from addiction/alcoholism can often create rapid changes in emotional maturity.
Absent that, my life was one long drawn-out example of “fear of missing out” and I flitted from thing to thing, place to place.
Just make sure you marry above your station, emotionally.