How to avoid confirmation bias?

When finding Product-Market fit, I see many entrepreneurs who: - Get super excited when they receive positive feedback: "This 1 prospect shows a bit of interest, wooooow this is amazing 🥳" - Tend to dismiss negative feedback "10 prospects believe we're building the wrong thing, it's because we didn't sell well [insert an excuse]". How do you differentiate your positive optimism and your own biases?