Who is John Laroche from The Orchid Thief and what is their importance?

The inspiration behind the book and Susan Orlean's article in The New Yorker, John Laroche is an extreme person. Originally, Susan believes that John is a unique, one-of-a-kind individual in general. As time progresses and she spends more time with him, however, she labels him instead as someone who is just extreme. He has many of the same traits as the average person, but his traits are pushed to an extreme by a personality that is "all or nothing." Physically, he is a tall guy, "skinny as a stick" with slouch-shoulders and pale eyes; Susan sees him as handsome despite the fact that he is missing some of his front teeth.