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.
You might think that Mario 64 was built with tickets and sprints, but, according to interviews, there was no master plan, only the principles that the game should feel good and be fun. They started with just Mario in a small room, and tuned his animations and physics until he felt nice and responsive. After that, the levels were also created as they went, with the designers, developers, and director going back and forth using sketches and prototypes.
Building like this is never a straight line. Ideas and code get left on the cutting room floor because part of innovation is questioning whether what you made should exist. The process is cyclical and iterative, looking something like this.