I think you underestimate how long Photoshop has been around... I started using it in 1995, and it was already onto PS4 by then. It was ubiquitous in the publishing industry long before camera phones were commonplace.
It's ubiquity I'm thinking of. The first cameraphones were around during Season 9 of the X-Files, probably even before, but not everyone had them. Same with Photoshop, it's only in the last six or seven years that the idea of photo manipulation for the masses has truly become accepted, and more importantly, the average Joe really started using it.
EDIT: It's a question of how long the word 'shopped has been in common use as a verb for manipulated images.
"Don't try to live so wise. Don't cry 'cause you're so right.
Don't dry with fakes or fears, 'Cause you will hate yourself in the end."
Anime @ MyReviewer