Why do many people dislike city life?

Many people who live in cities say that they dislike city life. (11)They say tile city is noisy, dirty and crowded. They are tired of the traffic and the pollution.
    But not many people living in cities are happy when they have to stay in the country for two or three weeks. (12)They enjoy the quiet, the clean air and the beautiful healthy surroundings, but they miss the stores and restaurants, the movie theater, the crowds, and the excitement of the city.
    People who live in tile country on the other hand (14)enjoy visiting the city for a day or an evening to do some shopping or go to the theater or a concert. (15)But they often find the city a rather frightening place and are usually happy to gel back to their quiet, unexciting lives in the country.