How Do You Know When You Have Product Market Fit?

The question is, how do you talk to your users if they have a problem they don't want to talk about? Es, type two diobedes. Im i am perfectly confident that you can find ten people who wants to talk about their type two diabedes. Am, if i were to summarize, i would say, how far along are you before you talk to investors? I am also going to pont on that answer.