A man does not qualify as rational if he walks around in a daze but once in a while, when someone mentions a fact, he wakes up long enough to say "I'll accept that," then relapses again.
Rationality requires the systematic use of one's intelligence.
Ayn Rand's novels abound in instructive examples of this aspect of virtue. Consider, for instance, Howard Roark's encounter with the Dean at the beginning of The Fountainhead. The Dean tells him that men must always revere tradition. Roark regards this viewpoint as senseless, but he does not ignore it. Roark is not a psychologist, nor does the field interest him much; but he does deal with men, he knows that there are many like the Dean, and he is on the premise of understanding what he deals with. So he identifies the meaning of the event in the terms available to him. There is something here opposite to the way I function, he thinks, some form of behavior I do not grasp—" the principle behind the Dean," he calls it—and he files this observation in his subconscious with the implicit order to himself: be on the lookout for any data relevant to this problem. Thereafter, when such information becomes available (new examples or aspects in new contexts), he recognizes and integrates it. In the end, by a process whose steps the reader has seen, Roark reaches the concept of the "second-hander"—and of the opposite kind of man, whom he represents. At that point, he grasps what the issue is on which his own fate and that of the world depend.
Whatever the heroes in Ayn Rand's novels deal with, including work, romance, art, people, politics, and philosophy, they seek to understand it, by connecting the new to what they already know and by discovering what they do not yet know. They are men and women who like and practice the process of cognition. This is why they are usually efficacious and happy individuals, who achieve their values. Their commitment to thought leads them to a sustained growth in knowledge, which maximizes the possibility of successful action.
In citing the Roark example, I do not mean to suggest that rationality has to involve the discovery of new ideas. The exercise of reason applies within the sphere of each man's knowledge, concerns, and ability. The point is not that one must become a genius or even an intellectual. Contrary to a widespread fallacy, reason is a faculty of human beings, not of "supermen." The moral point here is always to grow mentally, to increase one's knowledge and expand the power of one's consciousness to the extent one can, whatever one's profession or the degree of one's intelligence. Mental growth is possible on some scale to every person with an intact brain.
"Objectivism: The Philosophy of Ayn Rand", Dr. Leonard Peikoff, p. 222-223.