Alan Moore on The Smiley face

"The smiley face is evidently the purest symbol of innocence the human race has been able to come up with thus far."

Alan Moore

Though it was the most famous, it seems that the Watchmen wasn’t the first time that Alan Moore used the smiley face motif in his comics.

It was August 1983. Alan was making a name for himself with his phenomenal work on Warrior Magazine and was just 5 months shy of seeing his first issue of Swamp Thing hit the shelves. He also did writing for other magazines like 2000 AD and even managed to pick up a job from Marvel UK writing Captain Britain. He was having fun writing about hologram generating computers, fairy worlds and “Supreme Omniversal Tribunals” that make rulings for all alternate realities. While Captain Britain is fighting alternate versions of himself a killer cyborg from another reality lands on our Earth. He is hungry and needs to feed. A poor hapless bag lady will do. 
 

Daredevils #8, August 1983

When the first issue of the Watchmen came out 3 years and one month later who remembered that the smiley face was an old motif for Alan?

An excerpt of Alan Moore speaking about the smiley face motif from David Kraft’s Comics Interview #65 (1988)

“The Smiley button reflected the tone of the series (Watchmen) on a number of levels. 

The first page of The Watchmen #1

We found out while working on the book that the smiley face originated in a series of behavioral experiments with children. They were experiments to find the purest image of affection that a baby would respond to, and the smiley face is apparently it. The smiley face is evidently the purest symbol of innocence the human race has been able to come up with thus far. 

The last page of The Watchmen #1 showing symmetry with the first page.

In that sense, putting a bloodstain across the eye of the face allows for a number of interpretations. There’s the idea of smiling through the blood, the idea of a bloody joke, 

which, after all, is a symbol of innocence, and since superheroes have also represented a certain naïveté and innocence, you have a sense of lost or bloodied innocence, the end of this idea of truth, justice, and the American way. The very naïve notion of superhero goodness gets bloodied and knocked about. 
 

The last page of The Watchmen #12 showing symmetry with the first page of #1

There were a few other resonations there, but I think those were the principal ideas.”