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.
The “case study?” column was the whole point of the spreadsheet — identifying which projects I still needed to write up for my portfolio — but at this point I looked at the sheet, and thought “This is honestly a better overview of the work I do than any ‘portfolio’ I’ve seen”.
So I tweeted a screenshot, joking/trolling that it WAS my portfolio (I didn’t include any winks or notes that I was still planning a “real” portfolio), but people didn’t respond with the lulz I expected — they got the idea, or took it at face value and said they were going to do their portfolio this way too!