You should expect a certain amount of fear as a natural adjunct of your desire to speak in public, and you should learn to depend on a limited amount of stage fright to help make you give a better talk. If stage fright gets out of hand and seriously curtails your effectiveness by causing mental blocks, lack of fluency, uncontrollable tics, and excessive muscular spasm, you should not despair. These symptoms are not unusual in beginners. If you make the effort, you will find the degree of stage fright soon reduced to the point where it will prove a help and not a hindrance.
