Speaking of how nicknames come and go, when I was in Jr. high school, there was a guy who had really scraggly facial hair. Really scraggly. So, we promply nicknamed him "Fungus". It stuck. EVERYBODY called him Fungus, even the girls and the younger grade boys. It got to the point that kids didn't even know what his real name was. Even kids in OTHER SCHOOLS didn't know his real name but if you asked them, they knew who Fungus was. His mother used to get pissed back when people would call and ask her "Is Fungus there?".
The thing was, he was a really great guy, really popular, and funny as hell. He took the Fungus thing in stride. By the time he was in his Jr year, we pretty much relented and just called him Gus instead. And even though it's been years since I've seen him, I hear that's still his nickname to this day.