Barnum treats vocation not as arbitrary but as a matching problem. Natural aptitude must align with Vocation, or the worker fights uphill permanently. Even the right vocation fails in the wrong setting, because location determines demand. The safety net beneath both choices is practical skill, which protects against reversal of Wealth regardless of circumstances. When aptitude, Location, and skill converge, excellence becomes self-rewarding, there is always room at the top for the person who masters their craft.