I think this is something that happens to a lot of practitioners, especially if you have been working in the same job for a perid of time. About a year ago, I suffered from 'itchy feet' as I was not getting much job satisfaction, even though I enjoyed my work. I discussed this with my manager, who luckily was very understanding, and we came up with ways to develop my role, such as mentoring and research. I found that this gave me a new lease of life and has actually helped me consider where I want to be in the future in terms of my professional development.