The irony here is that Ambrose would be spinning in his grave if a pope told him that he must accept the dogma of the IC.What a joke! He's already in heaven; he knows the truth. And if you can't take Mary's word for it ... what can I say? Nothing!
Finally, it is also interesting that in several apparitions of our Blessed Mother, she herself has attested to her Immaculate Conception: On December 9 (the date for the Solemnity of the Immaculate Conception in the Spanish Empire) in 1531 at Guadalupe, Mary said to Juan Diego, "I am the perfect and perpetual Virgin Mary, Mother of the true God, through whom everything lives...." In 1830, Mary told St. Catherine Laboure to have the Miraculous Medal struck with the inscription, "Mary conceived free from sin, pray for us who have recourse to thee." Lastly, when she appeared to St. Bernadette at Lourdes in 1858, Mary said, "I am the Immaculate Conception." --Link.
You’re joking, right? Think of the sensibilities of those of us who do not believe in apparitions of Mary on pieces of toast. Mary said no such thing. Mary does not appear to people. These are the imaginative notions of a superstitious lot, sanctioned by a hierarchy willing to give the people what they want in order to keep them in line at all cost.