This can be seen as an illness. One that affects many urban dictionary editors, thus causing them not to be able to get your jokes, even if they are meme-based. The affliction will cause the the editor's hands to freeze and not to google to see if the definition actually holds water (they rejected 2deep4u, a popular /mu/ meme, countless times). Meanwhile, they're busy fapping away at stupid made-up bullshit.
Jim: Hey guys, this is Samantha
Sam: just call me Sam
Tom: Do a barrel roll!
*room erupts with laughter*
Sam: oh haha...
In that example Sam is meme-oblivious to do a barrel roll.