Long before he became CEO of Goldman Sachs, David Solomon got a tough lesson from his father after complaining he never had enough money: the problem wasn’t cash. It was time. Growing up in upstate New York, Solomon kept a packed schedule: three sports, student government, and shifts scooping 31 flavors at Baskin-Robbins. But he still didn’t have enough cash to do what he wanted. When he complained to his father, a businessman, Solomon expected…