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 all evidence of civilization on Earth was destroyed, and humans had to re-build society from the ground up, what would be different? Feynman reckons that pivotal scientific moments, like the discovery of the atom, will still happen in the same way. Perhaps mathematics will be similarly rediscovered.
Someone told me once in response to this question, no artwork would ever be recreated. The art we create – music, stories, dance, film – isn’t a fundamental element of the universe, or even of humanity. It’s unique to each artist. If you choose to create art, you leave something in the world that has never had a chance to exist before, and will never again have a chance to exist. There will never be another Beatles or Studio Ghibli or Picasso. Art, in its infinite variations of originality, is cosmically unique in a way the sciences will never be. Art immortalizes human experiences that would otherwise vanish in time.