Within a short time, you cannot become a guru in every field. However, you should know well the basic skills in some field. Let me say you have a thorough understanding of Jason Hunter's Servlet Programming. You have run all the code in the book. At the same time, you have tried to write your own code. Now if you go out for a job, if you happen to meet an interviewer who asks you a lot of Java Servlet and JSP questions, you may get the job. Job=skill + chance.