The Importance of Passion in an Interview
Although many job interview books and articles focus on technical questions, they typically at least touch upon the importance of dress, communication skills, general people skills, and likability. However, there's one aspect that seems rarely discussed relative to its importance: passion.
Wikipedia describes passion as "an intense emotion compelling feeling, enthusiasm, or desire for something." Letting other people know about your passions is an effective way to become more interesting and form connections with others. Whether you have a passion for writing elegant software or creating innovative products, it is important to show it in your daily life and crucial to show it during a job interview. While everyone is passionate about something, many aren't as good as naturally showing it as others. For example, I often inadvertently don't show enthusiasm about my work. It's not that I'm apathetic, I'm just not naturally an enthusiastic person. It's a bad habit that I'm working to improve.
Letting job interviewers know that you're passionate not only shows that you care for your work, but it also increases your likability as a person. Mutual passion for an activity acts as an effective icebreaker and can easily improve your relationships with others. In addition, if you're applying for a job, chances are that both you and your future boss have a passion for your field of work. For example, if you're applying for an iOS developer position at Apple, both you and your potential employer are probably passionate about programming and Apple's products. If this is not the case, then you probably don't want the job anyway.
Being enthusiastic about your passions will aid in making a connection with your potential employer and improve your chances of landing that job you desire. If you want to be more likable and have a better chance at getting a job you love, don't be shy with your passions.
 - Page 20 of Guy Kawasaki's book, Enchantment.