Personal Experience

The reason is that personal experiences are a terrible way to learn something. As human beings, we are all subject to preconceived notions, personal biases, and differing expectations; and of course any one person’s personal sampling of something is, by definition, an uncontrolled, unblinded test subject to external influences and all manner of unknown variables. This is why we all know people who have reached opposite conclusions based on their experiences. They can’t all be right, and that’s proof enough that personal experience is an unreliable way to learn practically anything.

Brian Dunning