The real challenge of the twentysomething years is the work itself. Ten thousand hours is five years of focused, full-time work (40 hours × 50 work weeks a year = 2,000 hours a year × 5 years = 10,000 hours) or ten years of less-targeted work (20 hours × 50 work weeks a year = 1,000 hours a year × 10 years = 10,000 hours).
