A childhood belief about swearing

When I was in second or third grade, my parents were visiting a friend, and I got into a conversation with their boy, who was the same age as me, about rhymes. So we made up this game where we'd take a word, and then go through all the consonants of the alphabet, and determine whether or not there was such a word. One word that we decided to play with was 'luck'. We started through the alphabet saying, "There's such a word as 'buck', there's no such word as 'cuck', there's such a word as 'duck, there's no such word as 'fuck', there's no such word as 'guck', etc. Neither of us had never heard the word 'fuck' before, since our parents never used it. When we got to 'puck', we said there was no such word also, since neither or us had ever heard of hockey. We thought this little game was rather silly, so we kept it to ourselves because we didn't want our parents to think we were too silly. A year or two later, our family moved to California, and a new friend of mine introduced me to the word 'fuck', with fair warning that it was a nasty word. Shortly after that, I saw the word spray-painted on the side of a building, and I said, "That's a nasty word." I told my parents later on how I found out it was a nasty word.