Myth: RCs believe the communion "hosts" magically turn into the literal blood and flesh of Christ before they consume it. Therefore, they are cannibals. (Fact: I've never met any RCs, including priests, who believe it is anything more than a blessed symbol.)
Christ said, "This is my body... this is my blood." Catholics take his word for it and have so for the past 2000 years. Just because dissenters in the US don't believe it, doesn't change the fact that at Mass, the wine and host becomes the body and blood of Christ.
Myth: RCs believe they are the one and only true religion. (Fact: RCs believe they are one of many paths to God.)
In the declaration, Dominus Iesus, by Cardinal Ratzinger, now Pope Benedict XVI, it is written thus: The intention of the present Declaration, in reiterating and clarifying certain truths of the faith, has been to follow the example of the Apostle Paul, who wrote to the faithful of Corinth: ?I handed on to you as of first importance what I myself received? (1 Cor 15:3). Faced with certain problematic and even erroneous propositions, theological reflection is called to reconfirm the Church's faith and to give reasons for her hope in a way that is convincing and effective.
In treating the question of the true religion, the Fathers of the Second Vatican Council taught: ?We believe that this one true religion continues to exist in the Catholic and Apostolic Church, to which the Lord Jesus entrusted the task of spreading it among all people. Thus, he said to the Apostles: ?Go therefore and make disciples of all nations baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all that I have commanded you' (Mt 28: 19-20). Especially in those things that concern God and his Church, all persons are required to seek the truth, and when they come to know it, to embrace it and hold fast to it?. 99