“Retrospectively, he realized that he had made a grave miscalculation when he had ended the friendship with Sadie. His mistake had been in thinking the world would be filled with Sadie Greens, people like her. It was not. His high school certainly hadn’t been. He had held out some hope that Harvard might be, but the college had proven especially disappointing on this front. There were smart people, yes. There were people with whom you might have a decent conversation for twenty minutes. But to find someone who you wanted to talk to for 609 hours—that was rare.”