Whenever he needs any information, he picks up that book, isn’t it? Similarly, suppose you are a mathematics professor, you don’t have to keep all the formulae in your memory all the time.
When you want Trigonometry or Algebra, at that time you take it; you only focus your attention and pick that knowledge with the memory.
It is the same thing with knowledge. All knowledge is available as a possibility, but it depends on our ability to pick what we can.
In order to do this, you need to have the ability for intellectual analysis and intuition.
Intuitive ability will help you get access to subjects which you have not intellectually acquired.
For every innovation, you need both (intellect and intuition).
It is not enough if you have just studied, and have intellectual abilities.
For innovation, you need an intuitive insight as well.
That intuitive insight comes when you empty your mind a few times every day.