When I was working with developmentally disabled adults, there was one man, whose intellectual level was around that of a five-year-old, who had trouble believing that anyone had been born before him. Last I saw him, he was 39, and the oldest he’d accept anyone else being was 32 or 33 (if you’d lived past that age, he’d give you a new one; most often it was 27). There was one instance, though, when he conceded to the facts. “My mom’s gonna be 81 this weekend,” he announced one day, his eyes as wide as if he’d witnessed a miracle. “That’s older than me!”
He made me realize that a big step in mental development is recognizing that your life has a starting point. The notion doesn’t come to us naturally: for a good stretch of childhood it’s as ungraspable as death.