There are two consistent themes running throughout this book: individuality and commonality. These are not contradictory, but rather complementary aspects of understanding how variations in fundamental cognitive processes colour and shape the everyday behaviours and experiences of individuals with specific learning differences. Because the cognitive profile of strengths and weaknesses varies from one person to another, diagnostic categories are imperfect, in that they imply uniformity and clear-cut boundaries. The reality is very different. It is these elements of individuality and blurring of boundaries that have led a number of individuals with specific learning differences to prefer the description of being neurodiverse.