After losing sales because he couldn't accept credit cards as a young, independent artist, this glass blower invented Square (NYSE: SQ), enabling not only his artist friends but literally millions of small business owners to process credit cards with mobile phones. Now, this remarkably humble billionaire is building his next transformational idea, all while remaining unchanged from his family-centric, Midwestern roots. In spite of his obvious success and many gifts, our latest Up2 guest is so self-deprecating, he reminds himself to, 'Shut up and try not to embarrass yourself.' ... Could just be our most meaningful conversation yet.