During your endless round of interviews, you will undoubtedly be asked what your weaknesses are. You do not want to tell the potential employer that you don't have any, and you definitely don't want to give positives as a weakness ("I work too hard!")
This article actually gives excellent advice on how to answer this question, and the most important part is, they tell you to follow up the weakness with steps you are taking to correct it. It tells the employer that you know your areas of improvement and work to implement a fix to these deficiencies.
I didn't write this article, I am simply sharing because I found it useful.