My grandparents are the only ones that ever called me Jon-Jon. My grandfather still asks about me by this name which tends to put a smile on myf ace. Occasionally my mom will slip into this but only when there's something extremely important or dire being discussed at that point in time.
As far as WB/Dub/Dubble goes I get asked this all the time:
"WB" started out in college at Tennessee State. Half of my friends there barely know my real name is Jonathan considering I was called by that name so much. Strangely enough it was started by a roommate of mine that I later came to dislike, based on my art style (WB standing for Warner Brothers, my favorite animation company at the time)
"Dub" was the "shortened" version of WB which is what friends online and my college buddies down in Savannah called me, and is currently what I am known by from the largest amount of people.
"Dubble" started here and in a few places where I couldn't register Dub or WB because they were too short. Dubble simply meaning "Dub 2".
And that's that
Jam it back in, in the dark.