U.S. government debt stands at more than $21 trillion. Does it matter? CNBC’s Elizabeth Schulze explains. ----- Subscribe to us on YouTube: http://cnb.cx/2wuoARM Subscribe to CNBC Life on YouTube: http://cnb.cx/2wAkfMv Like our Facebook page: https://www.facebook.com/cnbcinternational Follow us on Instagram: https://www.instagram.com/cnbcinternational/ Follow us on Twitter: https://twitter.com/CNBCi