Humans vary considerably from one another– with each of us having an idiosyncratic, subjective viewpoint.  How inter-individual variation in behaviour relates to diversity in brain function is poorly understood. In my talk, I will focus on brain-fingerprints, a set of functional neuroimaging features that reliably distinguish individuals from one another.  I will describe work from my PhD studies at McGill University on brain-fingerprinting and its application to clinical and cognitive neuroscience. Individuals can be robustly differentiated from one another using brief neurophysiological recordings from the spatial distribution of fast neurophysiological dynamics. These brain-fingerprints can differentiate individuals with recordings performed weeks apart and relate to cognitive abilities like attention. Individuals with Parkinson’s disease can be reliably differentiated from one another based on rhythmic brain activity in the sensory and motor cortical areas. Idiosyncratic neurophysiological profiles are driven, in part, by genetics: The brain-fingerprints of monozygotic twins are significantly more similar than dizygotic twin pairs. The impact of these genetic determinants on psychological traits increases across neurodevelopment. I conclude the talk by discussing how brain-fingerprinting research may inform future work on personalized cognitive models of health and disease.