In a thread on A Rationalist's Tale, lessdazed wrote:

Being levels above in [rationality] means doing rationalist practice 101 much better than others, [just like] being a few levels above in fighting means executing a basic front-kick much better than others.

Eliezer replied:

I regret that I only have one upvote to give this comment.

You may have noticed I write mostly about the basics of rationality, and lessdazed's comment explains why. There's something like the 80-20 rule going on here: 80% of the benefits come from 20% of the rationality skills. We aspiring rationalists don't usually fail because we failed to account for the optimizer's curse, but because we fail at a more basic level: we fail to say "oops", or we decide we have an incurable disease called "akrasia" instead of doing that which is known to fix akrasia.

More writing on the basics of rationality is needed, especially if it involves exercises and training in addition to reading. Less Wrong could use more work on teachable rationality skills, like the skill of connecting your beliefs.