We miss the targets because "how" is not known.
We are missing many targets because the mechanism to command them is not known. 
We read something twice or three times but forget to express it before the audience because it was not in our memory at that crucial time. It occurs to all of us repeatedly. We find that we have not practised our lectures in our memory sufficiently. 
During the exam, we are not sure of ticking the right answer. We have not differentiated the options thoroughly. There are numerous examples of such designs in all spheres of our activities. 
When a statement is seen again and again for a longer period of time, it becomes ingrained in our subconscious mind. It comes to our conscious mind the moment we need it. 
Likewise, when we are attentive, we grasp more. Just listening without any care does not come to our comprehension. 
The factor "how" demands a lot of pain to gain something in our engagements. No pain, no gain, is always true. 
We read a book, but takeaways are meagre. The reason is that we have little interest in reading that book. 
We are not tired when listening to music. It is pleasant to our ears and keeps us tied. 
When we are doing something we love, we are not bored. It is a reality. Here, our love makes the paths of "how."
In sum, it is essential to know "how" when we are not bluffing ourselves. Normally, short cuts are not the mechanism for learning anything in the true senses.
For the same kinds of engagements, the element "how" may vary from person to person. In absence of how, we hope any thing in vacuum.