In "Didn't Know", ASTRO reminisces about his life before his fame and explains his childhood with a ridiculously good flow. It's a genuine great rap song, one that is a pure representation of East Coast hip hop, a story being told with no cursing. "Didn't Know" has that Brooklyn sound I've missed, this is what Jay Z use to be, a young dude spitting some real sh*t. You might remember Astro from the XFactor about 3 years back. He's come a long way and has…