You have several years of software development experience. If that's true, you aren't really starting your career now, you're just looking for a more stable position. I think that the distinction is important especially in interviews because without it you might be underselling yourself.
Do I need to make that distinction explicit? Companies are usually more interested in hearing what the employee can do for them rather than what the employee wants out of their career. Underselling myself is probably also due to my lack of career intelligence. I don't know how to take responsibility for a career. I don't know how to give it periodic maintenance. I'm always living in the now, looking for my next jobs…
Also, you may be passionate about things you don't have a lot of experience in yet. A company that's not sure whether you are right for them based on your experience, might reject you for having no passions or ambitions, or give you a chance when they think your passion and ambition fits the kind of things they do.