The dread Mysteries, full of such great salvation, which are celebrated at every Liturgy, are also called a Thanksgiving [Eucharistia] because they are the remembrance of many benefits, and they signify the culmination of God's Providence towards us, and in every way cause us to be thankful to Him.
A little fire softens a large piece of wax. So, too, a small indignity often softens, sweetens and wipes away suddenly all the fierceness, insensibility & hardness of our heart.