Yes, we have a map of 75 million thingies and how they interact in some ways ... but we don't really know what even the interactions of just two neurons "really mean," which parts of their many interactions are the important ones, how they change over time and so-forth.

It does we humans a lot time to figure what an artifact from an alien human civilization does, even a fairly simple one - and that figuring generally involves something like figuring out the "blue print", the "purpose", the "programming" and so-forth of such an artifact. These are all analogies with our own intentional processes.

"Figuring out" the brain even as if it was a human-created artifact seems immensely hard. Yet like DNA, the brain isn't human-created or created at least-all. It just happened, in ways whose understanding will clearly take a lot of unraveling to really understand.

Not sure where I'm going with this aside from awe of the challenge.