Everyone knows the typical entrepreneurial success story: A couple of entrepreneurs have a great idea, work their tails off to establish the business and, before long, they're set for life. Right? Hardly. Turnaround artist Theo van Dijk knows two things: First, young businesses that have survived the start-up years will face periods of stagnation. Second, every venture at some point reaches a complacent plateau, owners take their eyes off the ball,...