We’re simple creatures. Give us a long list of tasks—or even a string of numbers more than about 10—and we’ll forget or get mixed up. The Stoics understood this, which is why they focus on a relatively manageable amount of subjects or disciplines. Like a good coach, they’re not training their athletes in every area, just the most important ones.

Epictetus says there are three areas that we must train in as philosophers.

First, our “desires and aversions” (that we strive for the right things and avoid the wrong ones)

Second, our “impulses to act and not act” (so we know our duty in each and every situation)

Third, our “freedom from deception and composure” (so we have good judgement and see the world around us clearly)

Don’t worry about everything else or complex philosophical questions. Just focus your energy on these three areas. Consciously training in these three disciplines bleeds over to the rest of our lives in a positive way.