I know this because my middle school students have no idea who Jesus is. They rank the Christmas "story" of His birth right up there with Frosty the Snowman and Rudolph the Red-nosed Reindeer: fun holiday fluff that has nothing to do with their lives other than providing entertainment.
Did Jesus really exist? Maybe; they're not so sure. Was He God? Well, He did some pretty cool tricks; does that make Him God? He died for us, but not really sure why or what that means for me. It's just a cool story in a book we never read. We just heard about it once.
I realize many of my students don't go to Mass regularly. I also know that many Catholic students, whether they are in Catholic schools or in religious education classes, have NEVER had a conversation with their parents about the Catholic Faith - except maybe to grumble about Father's sermon or complain that the Church is asking for money again.
The idea that a life based on thankful service to Christ Jesus, in humility, faith and gratitude, is as foreign to them as life without the internet. It is unfathomable.
Those of us who have been granted the gift of faith MUST start talking about it. We MUST reach out to people. Their very lives depend upon it. We are on a mission from God.