6. What does psychology teach us?A、It is useless to have a dream.
B、You'll hardly get what you want.
C、It is necessary to set a goal for yourself.
D、You should be satisfied with what you get.
【正确答案】：C
【题目解析】：细节判断题。题干问心理学告诉了我们什么？定位psychology这个词，出现在第一段，原文为Psychology teaches that you do get what you want if you know what you want and want the right things. 可见你必须先知道自己想要什么。这和选项C中set a goal for oneself（给自己设定目标）是同义的。因此答案为C。