Scenario A: Somebody takes the meme "Hey class today we're going to finger paint" and beneath that it says "Kid named paint:" Then shows someone who's name is paint thinking their bout to get finger fucked by the whole class.

Then someone alters the second line to say, "Kid named Finger:" because it fucks the whole punch line up and makes it so dumb it's funny.

Scenario B: People start taking shitty anime themed memes and replacing the prominent character/subject in them with pictures of Mike looking like he doesn't give a fuck. Like some shit happens and then the last frame is Mike just randomly there. It becomes super popular and the practice becomes known as mike-posting and it eventually gets it's own subreddit.

Scenarios A and B combine