This is also a good working definition of “engineering”.
This metaphor allows for creativity, cleverness, novelty, esthetics.
Most of my software development, production of code, does not meet this standard, so is not "software engineering".
I liken curiosity to foraging. The problem space isn't well known, or poorly defined. Or just new to me. Let's go play, see what we find.
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As for your OC, your form of curiosity is yet another form of smart.
Some people are book smart. Some with better working memory are better at mental gymnastics. Some, like with your book summaries, are smart at generalization, distilling concepts to their essence.
I like to think my form of smart is fondness for metaphors. My contributions to humanity have come from noticing when apparently dissimilar problems can be reframed, using the parallel, applying notions from one problem to another. It's a bit like reframing an optimization challenge to look like Traveling Sales Person, applying all that prior work to a new problem set.
For me it's mostly defining the undefined. I don't do it for the sake of gaining knowledge, it's more like "oh, so that's how it works". I like the feeling of taking something that feels like a magical black box and systematically breaking it down to the point where it doesn't feel magical anymore. Often times you only need a little bit more than a surface level understanding to get to this point.