Third, learning is an acquired skill, and the most effective strategies are often counterintuitive.

Interference from other events can distort memory.

Providing dietary supplements of fatty acids to pregnant women, breast-feeding women, and infants had the effect of increasing IQ by anywhere from 3.5 to 6.5 points.

Short-term impediments that make for stronger learning have come to be called desirable difficulties, a term coined by the psychologists Elizabeth and Robert Bjork.

One of the best habits a learner can instill in herself is regular self-quizzing to recalibrate her understanding of what she does and does not know.

In fact, research indicates that testing, compared to rereading, can facilitate better transfer of knowledge to new contexts and problems, and that it improves one’s ability to retain and retrieve material that is related but not tested.

By mimicking the challenges of practical experience, these learning strategies conform to the admonition to “practice like you play, and you’ll play like you practice,” improving what scientists call transfer of learning, which is the ability to apply what you’ve learned in new settings.

Interleaving the practice of two or more subjects or skills is also a more potent alternative to massed practice, and here’s a quick example of that.

Mastery in any field, from cooking to chess to brain surgery, is a gradual accretion of knowledge, conceptual understanding, judgment, and skill.