Because people typically don’t leave jobs they are happy with, potential employers want to know what your reason was for leaving your last (or current) job. Is there an issue with you that will cause them to regret hiring you? Overall, it’s important that you keep this answer positive. Anything negative that you say will make it seem like YOU are negative. So, say what happened, but with as positive a spin as possible. Of course, the ideal answer is that you were very happy and successful where you were, but this opportunity was just too good to pass up. Read more.