Boots, blisters, and other lies I told myself
The most expensive lesson in walking is that the boots that feel best in the shop are almost never the boots that feel best at mile ten. I have owned four pairs. I have got on with exactly one of them, and it was the cheapest.
Lie number one: they'll break in
Some do. Some don't, and no amount of hopeful short walks will change their mind. If a boot is fighting your foot on day one, it's going to keep fighting. I wasted a whole summer being loyal to a pair that never once agreed to be worn.
Lie number two: it's the socks, not the boots
Sometimes it genuinely is the socks. Thin cotton is a mistake I keep making because I forget between seasons. But blaming the socks is also a very convenient way to avoid admitting you bought the wrong boots, and I've done plenty of that too.
The trick I wish someone had told me sooner: tape the spot before it hurts, not after. Once you can feel it, you're already too late.
What actually helped
Lacing that locks the heel down so it can't lift. Stopping to sort a hotspot the moment I notice it, even if it feels like fussing. And accepting that feet are just going to complain sometimes, and that a complaining foot at the end of a good day is a fair price. I still get it wrong. Just less often.