Penance means being very charitable at all times towards those around you, starting with the members of your own family. It is to be full of tenderness and kindness towards the suffering, the sick and the infirm. It is to give patient answers to people who are boring and annoying. It means interrupting our work or changing our plans, when circumstances make this necessary, above all when the just and rightful needs of others are involved.
Penance consists in putting up good‑humouredly with the thousand and one little pinpricks of each day; in not abandoning your job, although you have momentarily lost the enthusiasm with which you started it; in eating gladly whatever is served, without being fussy. (Friends of God, 138)