So many different perspectives from so many who have successfully walked the Camino. This shows you that no matter what shape you are in when you start, with a combination of common sense, respecting your body's limits and luck, you can get all the way to Santiago.
We haven't heard much from some of the many who don't make it though. I've met a lot over the years and I think they typically fall into two categories -- those who had some sort of acute injury, like a twisted knee, broken bone, sprain, etc; and those who just overdid it, decided to "power through", and paid the price later on.
For that second group, it's usually the case that a non-physical event makes you stop listening to your body and then causes big injuries -- trying to keep up with others, not wanting to let your partner down, not wanting to separate from your camino family, having a return plane ticket that doesn't allow for rest days, etc. For anyone who is walking the Francés from SJPP for the first time, I would say -- if you can, add an extra week to your "schedule" and do not be afraid to spin off from your group. If you surprise yourself and arrive as expected, then you have time to walk to Finisterre and Muxia. But if you need the rest, you will be able to take it, to give your body the healing time it needs to get back in walking mode. I've been walking caminos for way too many years now and I am constantly surprising myself -- some years I get to Santiago early and am able to walk on to the coast, and some years, I have taken those extra days and used them along the Camino when it seemed right. And one last suggestion -- reservations are like a noose around your neck and can be oh so bad for your body.
Buen camino everyone, Laurie