Xyzzy (who I met at my first Stamford ACPT in 2000) posted a report in the New York Times Crossword Forums about the following summer's Con Francisco which got me interested enough to join. Unfortunately, my eyes glazed over at all the weird flat types (which seemed nothing like the puzzles I heard about at the Con) in the first Enigma I received, and I let my membership lapse.
A year or so later, Hathor and Foggy (who I also met at that same ACPT) joined and got me to give it another chance. Once I started solving with my local group (Hathor, D. Ness, and Sue++), I learned what was going on in those flats and I grew to appreciate all the fun in those Enigmas!
First Issue: July 2000
“Toonhead” was a name I picked as my first internet account name back in the 1990s; it's from an old Cartoon Network program called “Toon Heads” which focused on particular animators and/or themes. I'm a big fan of cartoons of all kinds (animation, comic books, comic strips), so it was appropriate. The exclamation point was added a few months later because of the propensity in comic books to end sentences with a bang! (There are at least two people in the comics biz who spell their names with one: writer Elliot S! Maggin and cartoonist Scott Shaw!)