Answer:

No, we're not Roman Catholic.  But the word 'catholic' itself means 'full and complete.'  It is not just part of the title of the Roman Catholic Church; rather, it was meant as a description of what the Church believed.  The Orthodox are Catholic in the true sense of the word;  that is to say, we have the fullness of Christian life within the Church.  Fullness itself means that there is nothing left out in our understanding of the Christian Faith, which is in reality, extremely deep.  Although other Christian expressions have certain parts of the True Faith, they often exist alone, or without proper relation to other parts of it.  The Orthodox Church has guardianship of the 'whole Truth', and so one getting involved in Orthodox Christianity will find out many things they have never heard before in a church, but which usually answer inner questions people have often raised about Christianity.