You used one to help fix a problem with another. I was the last family I knew to get a CD player, so I know this one well. And I'm only 31.
When the cassette tape comes unraveled, the tip of the pen is used on the reel to get it back into place.
LOL, that's what I always used. I always liked the cassettes cuz they seemed to malfunction and wrap up far less frequently than those old 8 tracks!