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/2wuoARMSubscribe to CNBC Life on YouTube: http://cnb.cx/2wAkfMvLike our Facebook page: https://www.facebook.com/cnbcinternationalFollow us on Instagram: https://www.instagram.com/cnbcinternational/Follow us on Twitter: https://twitter.com/CNBCi