This is the fourth of Tim Urban's series on Elon Musk, and this time it's about some reasoning processes that are made explicit, which LW readers should find very familiar. It's a potentially useful explicit model of how to make decisions for yourself.
http://waitbutwhy.com/2015/11/the-cook-and-the-chef-musks-secret-sauce.html
But why do they not apply it? Either way, the self-help material doesn't wind up helping or harming.
Perhaps it is because most people are not nearly as free as they experience themselves to be. They think that they can learn, that they can know, that they can act, but in reality they mostly struggle with anything larger than choosing from a restaurant menu. They struggle even with no-brainers like not living as a couch potato. Why do we even have a short code for "couch potato"?
To elaborate on MattG's "doing shit differently is hard" hypothesis: implementing most kinds of self-help advice requires permanently adopting new habits, and implementing habit change is hard. We know from habit formation studies that in order to establish a new habit, you need to associate the habit with consistent rewards and triggers, so that each time that you encounter the trigger you carry out the habit, and you should also receive a reward on a fair number of the occasions that you carry out the habit. Furthermore habits can easily fall apart if the triggers aren't robust and flexible enough.