What kind of stupid shit would you do back when you were a teenager?

My friend and I were getting drunk off his dads liquor one night and we were bored as hell so we began looking up funny names in the phonebook. We found 2 names and decided to write a letter to one of them and put the other person as a return address and then mailed it. The next day in our infinite wisdom, we wrote a return letter, switching the addresses. We continued this for about two weeks before doing the same thing to two different people and started a tradition. Unfortunately there was no way to determine the result of our efforts so I'm not sure how the people reacted. The best I can assume is that it was a convoluted conversation attempt between the two parties trying to figure out why this was happening.