One saying that I've always tried to apply to product development is a great insight from Mark Rosewater from designing Magic for twenty years: "Your audience

One saying that I've always tried to apply to product development is a great insight from Mark Rosewater from designing Magic for twenty years: "Your audience is good at recognizing problems and bad at solving them". As soon as you presume that you know your customers problems better than you, you're in trouble, but it's totally appropriate to ignore the solutions they suggest to you.