The metaphor of cognitive misers could assist people in drawing lessons from risks, which is the possibility that an undesirable state of reality may occur. People apply a number of shortcuts or heuristics in making judgements about the likelihood of an event, because the rapid answers provided by heuristics are often right. Yet certain pitfalls may be neglected in these shortcuts. A practical example of cognitive misers' way of thinking in risk assessment of Deepwater Horizon explosion, is presented below.