"No matter how vast your knowledge or how modest, it is your own mind that has to acquire it. It is only with your own knowledge that you can deal. It is only your own knowledge that you can claim to possess or ask others to consider. Your mind is your only judge of truth—and if others dissent from your verdict, reality is the court of final appeal."
--John Galt in Atlas Shrugged by Ayn Rand
The fundamental intellectual attitude proper to an Objectivist is that of being an independent thinker first, and an Objectivist second. Any so-called Objectivist that accepts anyone as an authority over his mind is violating the philosophy of Objectivism at its root. An individual can learn concepts, methods and principles from others and obtain factual information from others, but if he is to be successful in finding truths and living happily, it is he who must judge for himself what is true and false by means of his own reasoning. He should not take anyone else's word on faith, including Ayn Rand's.
An individual should consider himself an Objectivist, not because he takes Ayn Rand's ideas on faith, but because he has come to an intellectual agreement with Rand through his own observation and thought. He may have learned a lot from her writings, but a part of actual, conceptual learning is thinking critically about what one is learning and comparing it to reality, thus making it one's own knowledge.
A student of Objectivism may suspend final judgment on the overall correctness of Rand's ideas, due to his incomplete understanding of them, while learning about her philosophy and its arguments. Learning about Objectivism is a long process, (years) so in some issues, the student may suspend final disagreements for a significant period of time, based on his understanding and agreement with major principles he has already learned from the philosophy. (1) At every point along the way, however, the student should always act on his own best judgment at the time. He should never just assume Rand was correct and act on what he thinks Objectivism advocates, when he hasn't seen a rational justification for it. If the student finds some tenet in the philosophy that, after an extended consideration of the evidence and arguments, he still would judge as incorrect, then he should make that judgment and regard Objectivism as wrong on that point. This attitude is inherent in being an independent thinker, and Objectivism wouldn't have him anyway, if he weren't (so to speak.)
To quote Atlas Shrugged again:
"Accept the fact that you are not omniscient, but playing a zombie will not give you omniscience—that your mind is fallible, but becoming mindless will not make you infallible—that an error made on your own is safer than ten truths accepted on faith, because the first leaves you the means to correct it, but the second destroys your capacity to distinguish truth from error."
(1) The student in this case is not putting Ayn Rand's mind or anyone else's before his own. He is simply taking into account the full context of his knowledge, including the fact that he regards Ayn Rand as having made brilliant, sweeping integrations in philosophy. Thus, he takes extra care to understand and objectively assess her arguments before dismissing them.