[frobozz]

One reason not to switch professions is affordability. Few established mid-career professionals can afford to either take time out to train and qualify in another trade, or jump back down to the bottom rung and take a junior role in something else.

If, at 60, you have paid off your mortgage, amassed some savings, and seen your adult children leave home, then you can consider it. However, by then, you only have 5-7 years left until your pension kicks in and 10 before cognitive decline starts to take hold (either may have already happened), so you will probably just plod on doing what you already know. You might not even have enough time to really get to the interesting part of being a whatever-your-new-career-is.

If at 60, you are still in the prime of your life, with 60 more years on the clock, and 30 more years of full cognition and physical fitness available to you, then the idea of a career shift becomes more attractive.

Even without the affordability question, there is likely to be a point in most people's careers where the pursuit of mastery stops and the doldrums set in. The longer the working life, the more likely you are to reach that tipping point at a point when you have time to do something about it.