If we do not plant knowledge when young, it will give us no shade when we are old.

Learning takes years to become useful, which is the awkward part. The effort comes long before the benefit, and the benefit arrives quietly as ease rather than as a reward. What you study now is not for now; it is for a version of you who will find things simple that would otherwise have been hard.

Planting is still available at any age, and today is the earliest remaining day for it. Pick one subject that would make the next decade easier and give it regular, unhurried time. Twenty minutes most days will outrun any burst of enthusiasm.