The Idiot by Fyodor Dostoevsky

The anger of the Epanchin family was unappeased for three days. As usual the prince reproached himself, and had expected punishment, but he was inwardly convinced that Lizabetha Prokofievna could not be seriously angry with him, and that she probably was more angry with herself. He was painfully surprised, therefore, when three days passed with no word from her. Other things also troubled and perplexed him, and one of these grew more important in his eyes as the days went by. He had begun to blame himself for two opposite tendencies--on the one hand to extreme, almost "senseless," confidence in his fellows, on the other to a "vile, gloomy suspiciousness."

By the end of the third day the incident of the eccentric lady and Evgenie Pavlovitch had attained enormous and mysterious proportions in his mind. He sorrowfully asked himself whether he had been the cause of this new "monstrosity," or was it... but he refrained from saying who else might be in fault. As for the letters N.P.B., he looked on that as a harmless joke, a mere childish piece of mischief--so childish that he felt it would be shameful, almost dishonourable, to attach any importance to it.