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.
The more wood you pile on a fire the more heat you get, and thus it is with God - the more you think on Him the more you are fired with love and fervor towards Him. He who loves the Lord is always mindful of Him, and remembrance of God begets prayer.