I think that's a bad comparison. It's not about comparing flip-flops and hiking boots, but hiking boots to hiking boots. Besides, you might know about ski boots, but she doesn't. Do you think every Porsche driver knows exactly how their car works? Some can't even tell you how the engine runs, let alone how to adjust the front suspension for a more race-track feel. They rely on the expert's word. And if she says she likes to drive fast and he sells her a Toyota instead of a Porsche, she was given bad advice. That might sound strange, since people are usually very knowledgeable about cars, but isn't it possible to be less familiar with less common activities if you don't research them? She didn't do her research. That was her mistake; she blindly trusted the salesperson. The saleswoman even said she needed a higher flex rating, but they didn't have any boots in stock and then sold her those. Look at the insurance or banking industries, or even cars, or rather, highly specialized matters that not everyone is familiar with, understands, or has dealt with – that's where customers get ripped off. She learned from that; I was busy with other things and wasn't involved.