The “M” stands for “Mary”, the Mother of God, to whom he holds strong devotion
His “Motto” or “Battle Cry”: “Totus Tuus”, “I am all yours, Mary”…”All to Jesus trough Mary”
It is the same Motto of the Consecration to Mary of St. Luis Maria Grignon de Montfort… following the same order of Redemption: God gave us Jesus through Mary, so now we give everything to Jesus through Mary.
The Pope made the Consecration when he was young studying to be a theater artist. Just after making it, a thought came to his mind: “I want to be a priest”… but I don’t want to be a priest, he reflected, I want to be a theater artist!… but the thought came back again and again and again… and he became a priest!… and then a Bishop, with the Motto of the Consecration… and then a Pope who choose the same Motto of the Consecration.