The basis for what I wrote is explained in
ON THE USE OF VERNACULAR LANGUAGES
IN THE PUBLICATION OF
THE BOOKS OF THE ROMAN LITURGY
65. By means of the Creed (Symbolum) or profession of faith, the whole gathered people of God respond to the word of God proclaimed in the Sacred Scriptures and expounded in the homily, recalling and confessing the great mysteries of the faith by means of a formula approved for liturgical use. The Creed is to be translated according to the precise wording that the tradition of the Latin Church has bestowed upon it, including the use of the first person singular, by which is clearly made manifest that “the confession of faith is handed down in the Creed, as it were, as coming from the person of the whole Church, united by means of the Faith.”
This is also found at the USCCB site in the article "Draft Translation of the Ordo Missae
The explanation I attempted to apply to this was based on a text of an address by Cardinal Arinze, and I appologize that I have not yet found that to pass it along.
St. Peter of Verona: The assassin struck him with an axe on the head with such violence, that the holy man fell half dead. Rising to his knees he recited the first article of the Symbol of the Apostles, and offering his blood as a sacrifice to God he dipped his fingers in it and wrote on the ground the words: "Credo in Deum".