It's dangerous to generalise about the human impulse to create art, but it does often seem to be linked to the experience of dark and painful places. HARDtalk’s Stephen Sackur speaks to Lemn Sissay - a renowned poet and playwright whose writing and performances lay bare his own intimate wounds. He was abandoned as a baby, rejected by his foster family and abused in public institutions of care. He has since been on a quest to understand his past and piece together his identity. Along the way how did he find a remarkable poetic voice?Image: Lemn Sissay, Credit: BBC