If you think about it, you may come to realize that's not really true. If the true reality of the Mass is that it's a mystery taking place on a supernatural plane, and that it's an act of sacrifice and worship directed to God, not to man, then which language helps you understand that reality?
The evidence all indicates that the Catholic faithful understood the reality of the Mass back when it was offered in Latin. Catholics used to understand that the Mass represented an "unbloody re-presentation of the sacrifice on the Cross of Calvary." Today when the service is in the vernacular, they haven't a clue.