The "cliff of confusion" he describes is a function of the Dunning-Kruger effect (http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect), which indicates that you don't know how bad you are at something until you get better at it. As an educator, the challenge is to make that cliff as unscary as possible and chart a path through the "desert of despair" so that you're not pushing too much at one time.
On the other hand, as a self-learner it's really really hard to get past the point where you've learned enough to know how much you have yet to learn, or in terms of the article, when you look over the cliff and see how HUGE your journey is becoming.
To a large extent, the article is an advertisement (in more ways than one) for guided learning, expressed in a pretty clear way.