In reply to Babika:
Expanding feet? Yes, me too. 41 in rock shoes (Mythos), 42 in approach shoes and running shoes, 43 in Nepal Extremes, and now been measured at 45 for a new pair of walking boots (Altberg).
I suspect it's partly that my feet have got a bit bigger owing to the increasing amount of time I've been using them (aka, in simple English, age!), and also trying boots on soon after walking rather than when not having done so. But it's also due to really careful, detailed measurement. Time will tell as to whether 45 is genuine: I'm having the Altbergs made specially (without the Sympatex lining), and only had an extended try-on in the shop.
One significant thing I've noticed after wearing properly width-fitted Altbergs is that, contrary to what I had thought, Nepal Extremes are actually pretty wide at the forefoot, though narrower than Scarpas at the heel.