At a barbecue at Kensington Palace earlier this month, Prince Harry confessed to a huge regret he's been harboring. After his mother Princess Diana died in a car crash in 1997, he went a long time without speaking about her death."Everything can be okay, but I really regret not ever talking about it for the first 28 years of my life," he said in a BBC video of the event. "I never talked about it."The barbecue was part of the royal family's mental-health initiative Heads Together . With support from Prince William and Kate Middleton, the campaign aims to destigmatize mental illness and emotional struggle like the one Harry experienced when his mother died.Prince Harry previously opened up about Princess Diana's death in an interview with People in May. "When she died, there was a gaping hole, not just for us but also for a huge amount of people across the world," he said."It's okay to suffer as long as you talk about it," he said at the Kensington Palace event. "It's not weakness. Weakness is having a problem and not recognizing it."