Thus, even if we accept that the people are deviously neurotic rather than outright irrational, we still must specify exactly how they believe that t… - Robyn Dawes

Two biases of memory, however, tend to enhance the illusory nature of our retrospective “understanding” of our own and others’ lives. The first is that we tend to overestimate specific events relative to general categories of events. The second is that we tend to recall specific events and to interpret them in ways that make sense out of a current situation—“sense” in terms of our cultural and individual beliefs about stability and change in the life course. Thus, memories, which appear to be beyond our control as if we are observing our previous life on a video screen, are like anecdotes in that they are often (inadvertently) “chosen for a purpose.” The result is that they will tend to reinforce whatever prior beliefs we have, just as anecdotes tend to reinforce the points they are meant to illustrate.

Again, irrationality can hurt, and here we have evidence that a particular form of it is widespread. The people accused around hurt, and the clients—be they children or grown adults—are hurt. Irrationality is not simply an amusing diversion provided by tarot cards or Ouija boards.

Believing you’re good at something just because you do it—without any information that you’re doing it well—is indeed irrational.