Cheerfulness, and supernatural and human optimism, can go hand in hand with physical tiredness, with sorrow, with tears (because we have a heart), and with difficulties in our interior life or our apostolic work. He who is perfectus Deus, perfectus Homo ‑‑ perfect God and perfect Man ‑‑ and who enjoyed every happiness in Heaven, chose to experience fatigue and tiredness, tears and suffering|... so that we might understand that if we are to be supernatural we must also be very human. (The Forge, 290)

Whenever we get tired — in our work, in our studies, in our apostolic endeavours — when our horizon is darkened by lowering clouds, then let us turn our eyes to Jesus, to Jesus who is so good, and who also gets tired; to Jesus who is hungry and suffers thirst. Lord, how well you make yourself understood! How lovable you are! You show us that you are just like us, in everything but sin, so that we can feel utterly sure that, together with you, we can conquer all our evil inclinations, all our faults. For neither weariness nor hunger matter, nor thirst, nor tears... since Christ also grew weary, knew hunger, was thirsty, and wept. What is important is that we struggle to fulfil the will of our heavenly Father, battling away good-heartedly, for Our Lord is always at our side. (Friends of God, 201)