It is essential to always revise and improve how we pay attention and how we practice. Without constant awareness (which naturally brings revision) one falls into mechanical repetition, which goes nowhere.
Importantly, cognizance is never mechanical. That is, even though it revises and observes, it does this is a constantly spontaneous and fresh way.
In addition, one should always study the teachings in the same way, with full awareness and a willingness to revise our previous understanding. In this way we constantly improve on mistaken apprehensions or misinterpretations. Sadly, many students do not do this, assuming that what they heard or read first was correct, so they do not need to go back a read or study again.
Those who think they know usually know nothing at all, while those who know they do not know actually know the most!