Economists are always adding little caveats to their statements, like “rational consumer.” Well, what’s a rational consumer? Just like a “reasonable person,” a rational consumer doesn’t exist. A rational consumer always make the right choice for the right reasons. Human beings don’t.
One of the reasons that we don’t make very good decisions is that we’re constantly deluding ourselves. Even people who insist that they do not delude themselves, but everyone else does, is guilty of a delusion. David McRaney chronicles the many cognitive fallacies that get us through our day in his blog You Are Not So Smart. These fallacies don’t mean that we’re intellectually weak; it just means that we’re human.