When he was 12 years old, the boy did something he only later realized probably hurt his seventh-grade teacher. It was minor -- he was, after all, a kid -- but in time, when he was older and wiser, he wanted to find this teacher and apologize. But the teacher seemed to have vanished. Over the decades, the man occasionally turned to the Internet, typing the teacher's name into the search box. He never found anything. He never quit looking. A few months ago -- by now nearly 39 years after this happened -- he got a hit.