It is important that you identify and appreciate what you consider to be your skills, abilities and personal qualities. Only when you do this can you then confidently demonstrate these on your CV and be able to market yourself effectively to potential employers.
An added advantage of assessing yourself is that you will be able to identify your weaknesses, and thereby plan to improve and upgrade them.
Being able to communicate your work experience and knowledge to an employer and also match their requirements is vital for successful job hunting. By using a little time and effort to assess yourself it will be easier later on for you to match and demonstrate your abilities to the needs of recruiters.