Why do dreams fail?

In the book "Of Mice and Man," the workers work every day and they earn a few money so it is hard to save money. In addition, some workers spend the money playing cards and buying alcohols. Other workers save the money and they make a plan with the other workers so they save the money together. However, one of them use their all money to play cards then they cannot do their plans. Therefore, most workers do not have dreams because they think it is impossible and they give up easily. In the book "To kill a Mockingbird," there is a slave system so black people cannot get their rights. They have dreams but it is hard to be come true because white people make limits for black people. It is so sad because anyone can have dreams but some workers and black people even do not have dreams. They think they can come true their dreams and they give up easily.