Most of us are judged in life by how quickly we can get things done. Because of this, it's hard to develop the opposite mindset: one of slowing down, getting centered, and relaxing.
Many yoga classes start with a transitional period between public life and the privacy of the practice. In this period, students can simply build awareness of their own breath in order to prepare mentally, physically, and spiritually for practice. For some students, this process of slowing down is extremely difficult. Continually rushing from one activity to the next, many people are used to being hurried and impatient, so much so that it's almost impossible to relax and get centered.
If this is true for you, ask yourself: Am I rushing because I'm under stress or am I under stress because I'm rushing? Is it always necessary to hurry so much? Would you be able to run your life just as effectively at a slower pace? If so, take some small steps to slow it down, one day at a time.