Here's a little history on how eating cereal became so popular.
Charles William Post
Charles William Post would get in on the act while recuperating from his second nervous breakdown in 1893. He just so happened to be at the same sanitarium that the Kellogg brothers attended. His visit there inspired him to open his own spa and to further his interest in coffee products and breakfast foods. By 1897, he was selling what is today known as Grape-nuts and his own brand of corn flakes otherwise known as Post Toasties.