A childhood belief about swearing

I didn't know some swear words were worse than others.
My third grade teacher pulled three of us into the hall and made us tell the bad words we were saying on the way to school. My friends said, " I said damn" and "I said shit," so to be different, I said " I said fuck." The teacher grabbed me and said, "Do you know what that means?"
I didn't, and I sure didn't say it again for a long, long time...