BEST ANSWER: To overcome this objection, you must point to the many ways you have grown and adapted to changing conditions at your present firm. It has not been a static situation. Highlight the different responsibilities you’ve held, the wide array of new situations you’ve faced and conquered.
As a result, you’ve learned to adapt quickly to whatever is thrown at you, and you thrive on the stimulation of new challenges.
To further assure the interviewer, describe the similarities between the new position and your prior one. Explain that you should be quite comfortable working there, since their needs and your skills make a perfect match.