Beliefs have little to do with the Observable Reality of the Universe. At best, they are based on misinterpretation and misunderstanding of some Real Events. For this reason, believers do not feel any need to verify anything. They don't like to discuss alternatives and feel offended/upset if anyone dares to challenge foundations of their beliefs.
In contrast, those who aim to "know" constantly seek verification of their knowledge in Observable Reality. They constantly seek and analyse alternatives in search for "better explanation". To test their knowledge they make predictions of future events on the basis of their understanding of past and current observations of Reality. Any disagreement of their "knowledge" with observable Reality causes them to revise and rebuild foundations of their "knowledge" from scratch. Hence, those who seek to know are bound to change their understanding as they evolve.
It is important to note, however, that at any stage of their evolution their conclusions are determined and limited by their Intellect and their Imagination. Can anyone know anything that he/she cannot imagine or cannot understand?
Those who begin to know, become aware how much they do not know. Rather that getting depressed by self-admitted ignorance, they expand the context of their analysis and seek methods to improve their ability to understand.
Those who "begin to know" avoid perception changing stimulants such as drugs or alcohol, simply because such people don't enjoy feeling any more stupid than they really are. They appreciate their ability to understand (=their Intellect).