I believe everyone has different views of what the "American Dream" actually means. All humans are born with the fact they want things that have obstacles in it. People are also naturally greedy. I agree there is an "American Dream" but human beings have high expectations on life, so they will be people wanting to have amazing, or good unexpected situations happening in their lives. .
According to the Constitution, being an American Citizen means you would have to be born here or have USA Citizenship. Becoming a Citizen in the United States isn't a piece of cake. It takes time. So, you're asking yourself, why is it so difficult to become an American? From the world's point of view, the United States of America is consider the best country, because we have a powerful economy system and a strong military force. The majority of Americans share similar dreams and traditions. Americans have holidays about every month, they celebrate a special event that has happen in the past or just celebrate someone special. A dream that most citizens in the United States have is to be in the middle class or higher. "American culture encompasses the customs and traditions of the United States, including language, religion, food and the arts. Nearly every region of the world has influenced American culture, as it is a country of immigrants, most notably the English who colonized the country beginning in the early 1600s. U.S. culture has also been shaped by the cultures of Native Americans, Latin Americans, Africans and Asians." - Zimmermann, Kim.
They are different types of Americans, each one of them have a different mindset. Their is racism and homophobia in the United States, that makes citizens of the United States not live in harmony. That's only two things that make Americans upset, but they're many more obstacles and criticism that Americans go through every day. One example of a challenge of being an American is, when you try to apply at a job that is well organized or simply professional, they will have high expectations for humans.