It has been two decades since the first ‘patient-specific’ 3D computational fluid dynamics (CFD) models of intracranial aneurysms were published in the American Journal of Neuroradiology (AJNR). ... It has also been nearly a decade since the Food and Drug Administration's approval of the first clinical CFD application: calculating pressure drops and fractional flow reserve (FFR) non-invasively for coronary artery disease. Nevertheless, clinical utility of CFD for cerebral artery diseases still seems like fusion energy—always at least a couple of decades away. It is therefore understandable that journal readers may view with some skepticism recent work in the Journal of NeuroInterventional Surgery (JNIS) and other journals applying CFD to cerebral veins. As we outline here, CFD modeling in venous diseases, while not without its own challenges, might have a more straightforward path to the clinic. This is because, as for FFR, it is the pathophysiology of the blood flow itself, rather than the impact of disturbed flow on the pathobiology of the blood or wall, that is of central interest.