New Zealand farmer Paul Sorenson has a unique connection with his colleagues - a team of sheep dogs. <p> For 40 years, he's worked to develop smarter and more intuitive training methods for fellow farmers, while grappling with memories of a difficult childhood. <p> Reaching retirement, the veteran dog whisperer passes his knowledge to the next generation of shepherds, and reflects on the sacrifices he's made to pursue his intense passion for dogs.