In 1880 Mark Twain invited William Dean Howells to join him in a club in which “the first & main qualification for membership is modesty.”

“At present,” he wrote, “I am the only member; & as the modesty required must be of a quite aggravated type, the enterprize did seem for a time doomed to stop dead still with myself, for lack of further material; but upon reflection I have come to the conclusion that you are eligible.”

Howells responded, “The only reason I have for not joining the Modest Club is that I am too modest: that is, I am afraid that I am not modest enough. … If you think I am not too modest, you may put my name down, and I will try to think the same of you.”