From what I've read, neuroscience is in its infancy and there is so much which still needs to be understood. The brain is immensely complex.

I don’t know why you’ve been downvoted. The amount of knowledge we know of the brain than is significantly much lesser than what we don’t know. Heck, we’re still not sure if SSRIs work by increasing serotonin, reducing inflammation or increasing plasticity. Maybe all 3 are related.

Evolution has had millions of years to work on its craft. We’ve been studying it for an infinitesimal fraction of that time. There’s nothing surprising here.

The fly's brain has been deconstructed to finer resolution in the last ten years. The three dimensional model looks like a weather system. The threads in hardware/software could be made to thinly approximate that brain functioning for a minimalist flying dragonfly embodied micro controller.

Some years ago, there was a renewed discovery of a ligament [0] in the human knee, that is thought to be important for stability, especially after sport-related injuries.

Also, the mesentery [1] is only recently discovered as a separate organ, a sheet of connective tissue that supports and protects the intestine.

[0]: https://www.bbc.com/news/health-24826323

[1]: https://en.wikipedia.org/wiki/Mesentery

The glymphatic system has been discovered only 10 years ago it seems. And it’s still not that well understood.

A lot of this is due to advances in imaging, particularly two-photon microscopy, that enable acquiring images (and video to some extent) in live subjects, e.g. mice and rats, below the top surface of tissue. For neuroscience, you can either thin the skull or install a window, and image more than 100 microns into the brain, in live animals that are anesthetized or otherwise immobilized. Here's a nice article with an overview of two-photon for this purpose (direct PDF link): https://www.hifo.uzh.ch/research/helmchen/publication/helmch... that paper was published a while ago now, but the basics are still relevant. Two-photon played a big part in the identification of the "glymphatic system" initially as well. The Nedergaard lab does a lot of imaging, and they've built custom microscopes as well. (Source: I used to work in their department, and I'm doing my PhD work in the same building. edit: in Rochester, not at KU, though I visited there when they were first outfitting the lab space in Copenhagen.