Whoever seeks joy in himself will be sad, but whoever seeks joy in God will always be joyful because God is forever.
(In Io. Ev. XIV, 2)
From infancy to old age, each age in all men has its own special beauty.
(De div. quaest. LXXXIII q.44)
Mary was happy because she listened and kept God's word. She kept the truth in her spirit more than in the flesh of her womb.