Once you see that an answer is not serving its question properly anymore, it should be tossed away. It's just their natural life cycle.
They usually kick and scream, raising one hell of a ruckus when we ask them to leave. Especially when they have been with us for a long time.
You see, too many actions have been based on those answers. Too much work and energy invested on them. They feel so important, so full of themselves. They will answer to no one. Not even to their initial question!
The hardest thing about customer interviews is knowing where to dig. An effective interview is more like a friendly interrogation. We don’t want to learn what customers think about the product, or what they like or dislike — we want to know what happened and how they chose... To get those answers we can’t just ask surface questions, we have to keep digging back behind the answers to find out what really happened.
If we reach such a very ordinary state of daily life, and then back it up with building and construction that comes from the depths in us, then that gradually accumulates our value in the world, all of us together as a whole. Later, then, perhaps hundreds of years later, people will look back at our stones and say to themselves, "My word, those people way back then — they certainly knew how to live," and they would say this because they could see the lingering whispers in the walls and mosses, and could read them, and could treasure them, and would learn from these traces how to live like that again.