Enthusiasm is one of the more powerful means by which we may put into ACTION our education, experience and knowledge.

Spoken words without ENTHUSIASM are often ineffective, and sometimes they can be actually boresome as you, of course know, if you have noticed the effect a speaker without ENTHUSIASM has on his listeners.
I have known lecturers to hold audiences spellbound for two hours, yet, when members of the audiences were asked to tell what the speaker had said they could not remember. But, what they did remember was that the speaker got their attention and held it.
Now let me explain how and why ENTHUSIASM has such a powerful impact upon the minds of those who come under its influence. To begin with I believe you will be interested in knowing that YOUR BRAIN and every other person’s brain is both a broadcasting station and a receiving station which sends out thought vibrations and picks up those sent out by other people.
When you turn on your ENTHUSIASM you step up the vibrations of the thoughts which go out from your brain so that they reach and affect other people more quickly. As a matter of fact you can send out thoughts which have been so stepped up with silent ENTHUSIASM that they will reach and influence other people to whom you direct your thoughts. This is a fact which has been known to psychologists for ages, and it is also known to most Master Salesmen who use this method to condition the minds of their prospective buyers before they ever talk with them.
You must have observed that ENTHUSIASM is very contagious—that it engages the attention of those who come under its influence and causes them to respond in a similar spirit of ENTHUSIASM.
I once heard Andrew Carnegie say that if you turned loose one man who thought in terms of intense ENTHUSIASM, in an industrial plant employing thousands of people, this man’s ENTHUSIASM would very quickly reach and influence every person in the plant. And he said that it made not the slightest difference whether the ENTHUSIASM was negative or positive, constructive or destructive.
Then Mr. Carnegie went on to explain that in his selection of employees for promotion to bigger jobs the first thing he looked for was a man’s capacity to express himself in terms of intense ENTHUSIASM. He said that ENTHUSIASM is one of the most important traits necessary for leadership.
Source: Video Series. Number Eight. Copyrighted television talks by Napoleon Hill. Subject: “Inspired Feeling” (Enthusiasm).