His birthday. His death day. Holidays. Family celebrations. That's when Linda Morrison feels the loss of her youngest son, Mike, most profoundly. But with time, she is finding more space in her heart for gratitude and hope—for the happy life Mike wanted for her. Morrison's achingly honest mother-son love story, Dear Heroin: A Memoir of Goodbyes, helps other families feel less alone in the darkness and devastation of addiction. Listen to her poignant interview with host William C. Moyers.