I suppose this all depends on how one views or defines nicknames - are we, for instance, merely talking about the pet names that come from familiarity only, or do we include the nicknames we choose for ourselves on the Internet?

• Most of my nicknames stem from my first name: Lo, Nita, Auntie Lolo (it's what happens when you know a young child - though I was a bit freaked out the other day when she called me by my name).
  
  
• Pangea was the first nickname I chose on the Internet, and that was the supercontinent before the separation of the continents into what has now necessitated the science of plate tectonics.
  
  
• charlie_brokentoaster, the name I have on MySpace (an account I pay little attention to anymore), was the name of my imaginary friend when I was little. I do not believe he was an actual toaster, as such.