A well-used dictionary contains many small admissions that guessing was not enough.

Every worn page marks a moment somebody chose checking over guessing. That is a small unglamorous act repeated hundreds of times, and it is most of what expertise is actually made from. People who know a great deal tend to be the readiest to admit mid-sentence that they are not sure.

Catch yourself this week at the point where you almost know something. Look it up rather than proceeding on a decent guess, even when nobody would have caught you out. The cost is thirty seconds and the return builds quietly over years.