Solve problems in ways that leave behind knowledge.

You can end a problem in a way that leaves you no wiser, and that is a poor trade even when it works. The version that leaves knowledge behind, a written note, a clear understanding, a method someone else can follow, costs a little more now and pays out every time something similar appears. Most people solve the same class of problem repeatedly without ever accumulating anything.

After fixing something, spend five minutes writing what actually caused it and what worked. Keep it somewhere you will find it. That habit is the difference between years of experience and one year repeated many times.