The middle-class man never learn this skill, they just work at a job, happily doing what others tell them to do, getting paid based on their bosses discretion.
Why let someone else decide what you are worth and how much you should be paid! Define your own worth.
Next, you may ask “How might I package up my interest as a product or service so that I can offer it to people?” Whatever ideas and possible answers you might have come up with, you need to present it to potentially interested people. Let them educate you on what they really want as opposed to what you think they want.
Here’s the difference: it’s highly unlikely these people will give you money for what you “think” they want. But, they’ll happily give you money for what they really want. Talk to various people, get that education, and create the products and/or services that they really want…
The fact is, everyone is in sales, and there are clients in whatever area of work you are in and you do need to sell. Learn to constantly promote your products and market your ideas.
Never underestimate the power of your dreams by not trying to promote your ideas. The potential for greatness lives within each of us.