I recently read a book with suggestions on creating characters. One of the suggestions that struck me as rather interesting was an assertion that main characters should not be developed as too smart, since readers wouldn't appreciate, or be able to connect to someone in that position. He brought up Sherlock Holmes as an exception, but then said it worked because his story was delivered through a much simpler filter character. This troubled me a bit, since making a main character who is clever doesn't seem like it would be off-putting, but do you suppose this is true? What are some examples of clever main characters that spring to mind? Is stumbling through life, unable to come up with solutions without lots of error the best way to write a character? Would a very knowledgeable person make a better villain in most circumstances? This is purely theoretical and for discussion, but I'd love to hear what you all think of characters being too smart for print/readers/publishing.