What Works for One Person Doesn't Always Work for Everyone

Leave the stadium five minutes early and you beat the traffic. If everyone leaves five minutes early, the traffic simply starts five minutes sooner — and you're back in it. A trick that works because most people aren't doing it stops working the moment everyone does. This is why so much popular advice ("wake up before everyone else," "buy before the crowd") quietly depends on not everyone following it.

Before adopting a strategy because it worked for someone, ask: does this work because of what it is, or because most people aren't doing it? The answer changes how much you should rely on it.