Just two short years ago, Lil Nas X was sleeping on his sister's floor. Now, he has the longest-running No. 1 single in Billboard's history. He returned to his Atlanta-area high school to inspire students there. "I was dreaming that last year, around this time, I would make a huge footprint in music, and I would get up there as quick as I could," the 20-year-old rapper told Gayle King on "CBS This Morning." InsideEdition.com's Stephanie Officer has more.