A childhood belief about prayers

When I was young we started attending church for a few years. I had never been in a church before, and was actually half-Jewish. Every Sunday the pastor would ask everyone to "say the prayer the Lord taught us", meaning The Lord's Prayer. Because he introduced it like that, and because nobody looked in their hymnals while they said it, I thought that it was so sacred that it wasn't allowed to be written down. I thought there was some long, mysterious ceremonial process to learning it, and that we would never be allowed to learn it or say it, since we weren't "really" Presbyterians. (To my mind, you weren't "really" a certain religion unless you were born into it.) I found it in a book at the library and memorized it in secret, as an act of adolecent rebellion. I couldn't for the life of me understand why Mom was proud when I spontaniously recited it to her after a fight.