I've thought a lot about this over the past year--especially around the release of The Gift of Being Different, the book I co-wrote with my youngest daughter Abigail. Our book became possible not despite Abigail's differences, but because of them! As Kabbalah teaches, what seems to be in the way often IS the way!
Because while the idea of "normal" may have its valid applications, the concept is inherently arbitrary and dependent on context. According to Merriam-Webster, "normal" (adj.) is defined as "conforming to a type, standard, or regular pattern; characterized by that which is considered usual, typical, or routine."
We measure height, weight, and growth charts by such curves from the moment our children are born. And then, there are grade level benchmarks, intelligence quotients, and standardized tests for pretty much every subject and college/post-grad degree. Later on, we define "normal" through averages--be it the average income, cost of a home, number of children, or age for retirement. The list goes on. And it's easy to pit ourselves and our friends and family against such defined norms.
We wonder, Is my child tall enough? Is she reading at the right age? Is he socially normal and well-adjusted? And that doesn't include our worries about ourselves! But even an intelligence test can be way off the mark if it's not given in a person's native language. And within each set of measures, there will always be those otherwise "normal" people whose results are atypical.