Why did Tchervyakov begin to feel uneasy?

Tchervyakov is 'a no less fine' government clerk and the central character to the story. One evening he visits the theatre to see opera. When he finds himself in the highest point of bliss, Tchervyakov suddenly sneezes and spits on a man in front of him. This is Brizzhalov, an important man from the Department of Transport, and Tchervyakov resolves to apologize. The man does not want to listen to Tchervyakov's apologies, he came to listen to the opera. Nevertheless, Tchervyakov still feels the need to explain himself and approaches Brizzhalov several more times in the theatre and also in his office. Eventually Brizzhalov grows frustrated with Tchervyakov and throws him out of his office. It is apparent, that Tchervyakov lives to please his superiors, and when he fails to make Brizzhalov like him, he goes home and dies.