Since the early days of my working life I have subscribed the view that you should always be planning your next career move, in order to keep developing professionally and (shock, horror) financially. Each of my moves was always planned with that in mind.
For example, I once held a middle management role in a small ticket, regional asset finance firm, with predominantly middle office responsibilities. Knowing that I wanted to experience (a) more complex financing products and bigger funding deal sizes and (b) front office duties, my next move was to an international bank in the City of London. I took a status and salary cut to do so, but this was because I was convinced that over the medium term this would benefit me both professionally and financially. The key thing was that this was very much a strategic move.
I think that any job where you work for someone else becomes stale and frustrating over time and I have felt this on several occasions over the years. I have, however, tried to avoid being led too much by these feelings as I realised that it might be just as much ME that was the problem as the place I was working. Fortunately, I have not suffered much from personality clashes. I have worked with more than my fair share of idiots, bone-idle wasters and glory-hunters, but they always did more harm to themselves than to me.
Having worked for myself for over 10 years, I have to say that the absence of organisational politics is a tremendous boon.
It is interesting, I think, to consider what people say when asked "if you didn't do what you do for a living, what would you want to do"? Hardly anyone says that they wouldn't change. I think that is quite sad, and makes me think of Henry David Thoreau's most frequently quoted saying - "the mass of men lead lives of quiet desperation."
Me, I would quite like to be a teacher if I had the opportunity ("Captain, my Captain", and all that). But somehow, I don't see it happening. The wife is already looking a plans for a new kitchen extension, so I guess I should get back to work now.....