MRIs are amazing from a technological perspective and we're lucky to live in a time when they're readily available (science is awesome). If you ever have an MRI and are able to collect the data, there are some pretty powerful and free tools that will allow you to create 3D models of that super computer between your eyes.
The images come in a standard called DICOM. Once I had them in hand, I started the arduous process of learning how to use FreeSurfer, a computational neuroimaging software that's maintained by the Laboratory for Computational Neuroimaging at the Athinoula A. Martinos Center for Biomedical Imaging (props to them for being curious and generous). Luckily, there were a number of guides online. Of course, things rarely transpire smoothly and there is a sizable amount of terminal work needed, if you're not somewhat comfortable using the command line on your Mac/PC this one might be tricky. It took my quadcore overclocked processor close to 8 hours to finish computing the 3D model once it started the process. Considering how fast a computer can "think"...this kind of blew my mind. Puns completely and proudly intended.
Here are some photos of my brain printed in PLA. I've yet to print a model to scale, I swear my real brain is bigger than this, I think.
Update 10/24/20: I've since printed my brain several more times in different colors of PLA and a flexible TPU filament. It's become my go-to test print when I'm calibrating my 3D printer. Behold...the brain tower.