Kelly Ripa is thankful for her time spent with the late Regis Philbin. In a preview from ABC's upcoming "20/20" special about the legendary TV personality, Kelly shared the greatest lesson she ever learned from her longtime "Live!" partner. "What I think my biggest takeaway from the 11 years that I shared with him was that you have to be yourself," she said. "You cannot be one person on camera and a different person once the light goes off or the audience is gone. You have to be who you are." Regis died of natural causes on July 24 at the age of 88. He and Kelly co-hosted the popular daytime talk show together from 2001 to 2011.