Motivational self help

I'm at a moment in my life where I'm looking for inspiration. I want to break the dependency to employers and start producing value for myself and not for somebody else. But for some reason, I cannot find any project or business idea that motivates myself enough.
This search for inspiration led me to self-help books. I first stumbled upon "Rich Dad, Poor Dad". In this book I found a reference to "Think and grow rich". This later book was fist published in 1937. It was inspired from Dale Carnegie who (according to Wikipedia) began the self-help movement in the 20th century with a book published just one year before. So we can consider "Think and grow rich" as one of the first modern self-help books. It's a motivational book to which many of the current self help books and blog ideas can be retraced. they all talk about perseverance as being the one condition that will ultimately lead to success. Sticking to one's dream and focusing all one's energy to its realization will prevent failure. All is about having faith in oneself and believing in the inevitability of success. To illustrate this idea, these books and blogs are usually littered with examples of men having changed the world with the strength of their conviction, such as Gandhi or Abraham Lincoln, or having become millionaire after having turned whatever idea into a thriving business.
I'd like to break this myth with a simple argument. How many people having dedicated all their energy during all their life in the realization of their dream never succeeded ? How many of them had the most unwavering faith but didn't make it ? We don't know for the simple reason that these men don't tell their story. They don't become public figures. Nobody knows or talk about them. They silently disappear in the anonymity of their failure. We only know about the ones that succeed. So what is the ratio of failure against success ? Just a bit of common sense can tell us that it is very high. So let's just be careful about not being taken away by all this motivational self help trend. Being positive is fine. Being unconditionally obsessed is wrong.