[SMrF]

The rapid iteration/pivot approach makes more sense if you start with something you are passionate about. That's the key. Maybe try only testing your assumptions about your market? Try to describe someone who would use your product and then find someone who matches your description. If they are not interested it's only one aspect of your idea. If your passion for this idea wilts after one encounter like this then either you aren't cut out for this gig or you weren't that passionate about it. Probably the latter, because if you have the guts to make a phone call to some random stranger you're already doing something 99% of people won't.