I own a few of his puzzle books, and even have solved some of their puzzles. Some are so amazingly difficult that it's hard to understand how someone could be

I own a few of his puzzle books, and even have solved some of their puzzles. Some are so amazingly difficult that it's hard to understand how someone could be that smart. Couple that with what everyone I've ever heard say about him, the person... that he was a wonderful, caring generous man. Amazing.