Analyze why is it remarkable to have the power to detach one's mind at will?

It is very easy for anyone to see why it is remarkable to be able to detach one's mind at will. All one has to do is to try to stop thinking. We all have ongoing streams of consciousness similar to those depicted more or less accurately by James Joyce in his Ulysses and by William Faulkner in his The Sound and the Fury. If we attempt to stop thinking we will find that we cannot maintain a blank mind for more than a few seconds. The yogis in India practice meditation by keeping their minds blank for longer and longer periods. No doubt some of them can do this for hours, or even days--but it takes practice and self-discipline. Here is a pertinent quotation from an ancient book translated into English by Christopher Isherwood.

This is the beginning of instruction in yoga.
Yoga is the control of thought waves in the                                   mind.
Then man abides in his real nature.
At other times, man remains identified with
the thought waves.
Patanjali’s first four sutras
How to Know God

What Patanjali means by "thought waves" is the same as the modern term "stream of consciousness." We all have these thought waves going on in our minds continuously. It is interesting to try to practice this form of meditation, which is also an important subject in the Bhagavad-Gita. For one thing, we realize that our stream of consciousness is not really "thinking," but something more like a car engine idling when the car isn't taking us anywhere. A lot of it is nonsense, and it is usually fragmentary and strongly influenced by free-association. If we can stop "thinking," then we can control our thinking better when we do want to think and have something important to think about. Sherlock Holmes evidently did not want to waste mental energy on daydreaming or woolgathering. His extraordinary mental powers, Watson suggests, were due to his being able to control his mind and to focus on a problem until the solution opened up to him.

It may be that all great thinkers such as Albert Einstein and Isaac Newton had the same ability to focus on a single problem until it seemed to solve itself.