Find your passion, follow your bliss, if you can dream it you can do it. Advice that sounds good in theory, but far too optimistic to be practical. The worst is "do what you love and the money will follow" because it's so painfully false it's almost the opposite of true. Nobody will pay you to do what you love, because they don't have to, because you'll do it for free, out of love. You get paid to do the things other people are either unable or unwilling to do. This is why web developers and sewer inspectors earn more than artists, musicians and people who knit hats for dogs. Unless your passion is tax law or business process optimization, you will be paid exponentially more to do the worst thing you can tolerate, and find your bliss after hours.
The simple fact is that very few people are exceptional, most are in the middle of the bell curve. Whatever you're best at, whatever you love to do, a lot of people are way better at it than you will ever be. At some point, you'll have to decide whether you'd rather follow your dream or eat.
In the post-industrial age, most of the worst jobs exist inside the offices of large corporate or government bureaucracies. The jobs all have different titles and descriptions and yet somehow end up being very much the same. You attend meetings, you create reports, you send and receive an incalculable quantity of email, and you find ways to work around the archaic and outright broken systems required by HR to prove you're doing the work you aren't, in fact, being allowed to do. In short, bureaucratic busywork. And it's this busywork that makes the job unpleasant enough that somebody has to pay you a decent salary to do it.
The message of Leash Your Potential is simple: don't expect to love your job, don't chase promotions and recognition. Find your level and stay there. Get good at the things most people view as impediments to your job because that's what you're actually being paid for. Learn to love the nonsensical and downright insane directives that show a complete lack of understanding from management, and find solutions that satisfy what you're being asked to do rather than what you know needs to be done. In short, fight stupid with stupid.