Photoshop

It's an ongoing joke, I'm not sure how to explain it without being offensive, because back in the 80's and 90's people used the term retard pretty casually, and somewhere along the way some comedian made the joke about a retard having to wear a helmet. I can't remember where it started, might have been mad TV, or in living color? It might have even come from Carlos Mencia, I think Timmy in south park might even have a helmet, it's just an old running joke. Whoever made the meme was probably an older millennial or gen x.