A childhood belief about church

As a protestant growing up in a catholic school, I was not used to certain catholic customs, such a recieving first communion around the age of about 8 or 9, (second grade). While not participating, I was required to attend my classmate's communion. When I saw them walk down to the front in white dresses and little suits, I thought the school was forcing my classmates to marry each other! I had belived this until I asked my teacher why they did this. She set me straight.