At no point during your education will your teacher or professor ever ask you to take anything they say and research. The reason for this is that in school you're taught what is an agenda, not really believed, even if there is some method for knowing that information that can be presented to you for your own verification. This is vastly different from teaching, which rely on the truth and verification incentive.
What reasons have we to suspect 6 million jews were killed? I will tell you: none. There exists no empirical evidence for such a lie. There exists no sound arguments for such either which explains why virtually all honest people are non-believers.
So why do people believe? Poor reasoning skills is the most common culprit. However, that's not the only one (and certainly poor reasoning skills are not exclusive to the believers). There are people with sufficient reasoning skills who still believe. These people either compartmentalize in order to preserve the belief (formed prior to their education in logic), or did not think about it enough which leaves them with an ambivalence. When attempts to reconcile such an hoax are made, one often chooses what one is taught over what one analyzes. This leaves such a person in a paradoxical state where they wish they could not believe (as a result of being aware that logically-speaking it is naive) but incapable of abandoning such a belief because of the nature of the overexposed lie.
At the end of the day, lies are irrelevant. What is important is what is known. It is alarming to me that children are taught holocaust as factual, as known, when in reality we know better.
Edit: this thread is an attempt to show how irrelevant a similar one is and does not neccessarily reflect the opinion of the author. NSA and JIDF are free to ignore.