You might never use the formula again. You’ll use the patience it took to solve it every day.

Most of what a hard problem gives you is not the answer. It is the experience of staying with something after the first three attempts failed and the urge to quit showed up on schedule. That tolerance is general purpose. The specific content fades, and the capacity to sit in not knowing follows you into everything else.

Notice where the urge to give up lands on the next hard problem, and how long after starting it arrives. Try staying five minutes past that point. You are building the part that transfers, whatever happens to the question in front of you.