Seneca · On good company
Letters 62.1
We are deceived by those who would have us believe that a multitude of affairs blocks their pursuit of liberal studies; they make a pretence of their engagements, and multiply them, when their engagements are merely with themselves. As for me, Lucilius, my time is free; it is indeed free, and wherever I am, I am master of myself. For I do not surrender myself to my affairs, but loan myself to them, and I do not hunt out excuses for wasting my time. And wherever I am situated, I carry on my own meditations and ponder in my mind some wholesome thought.
Seneca, Letters to Lucilius 62.1, translated by Richard Mott Gummere