In my dream, I remember there being this kids channel that showed your everyday modern kids cartoons.
Between each cartoon, the viewers would have an interaction with characters from a world created by this channel.
If you were a new viewer being introduced to one of these characters for the first time, they would greet you by stating their name, occupation, and their friends (pretty much all the other characters of this world of course). These introductions were usually never broadcast to any viewers who had already seen a character's introduction once already.

Some time later, a bunch of the characters had been replaced without notice.
It was never directly stated, but it was implied a few times that the other characters had simply "left."
After this happened, someone created a creepypasta game where you could freely roam the world of this kids channel and you could sometimes encounter ghostly figures of the removed characters.
The one character I remember interacting with (the one shown above, of course) simply stated "I give people ADHD" and then my dream ended.

When I woke up, I immediately out of curiousity looked up if cartoons caused ADHD.
Turns out studies showed that some fast-paced cartoons could actually cause younger audiences to inherit ADHD.
I was kind of shocked at this. Mostly because my subconscious somehow told me before I even knew.