Exactly, that moment when your feet are actually shredded changes everything. I remember wearing cheap sneakers on a rocky trail and coming back with blisters the size of quarters. Suddenly all the talk about quality footwear made COMPLETE sense. It's not just marketing, it's about avoiding real pain. You don't know until you've been through it yourself.
Back on a hike in Utah, I wore thick cotton socks with my boots. After 10 miles, my feet were soaked and rubbed raw. @kimhall is right about learning from pain, but for me, it was the socks, not the shoes. I had to duct tape my heels just to make it back to the car.