Some of the times a lack of self-assurance stems merely from a deficiency of experience. You might not feel so positive about taking the SAT test or giving a public speech if you've never done it earlier. These feelings will shift as you grow and experience more matters in your life.
Occasionally, however, a lack of self-confidence may stem from tones of insecurity. Occasionally we have foul feelings about ourselves and we bury them deep within. Once we do this, we tend not to assert ourselves and take a chance because we fear our "mysteries" will be revealed. Many people have never heard if this and have no idea how to go about figuring out where they are or how to change it.
Is this true for you? Then please continue on as you need to discover the secrets that increase your confidence!