Someone oblivious to a meme but awkwardly laughs anyway. Meme-obliviousness is normally apparent when a large number of friends are talking face to face (like irl), and one of them starts meme-spouting and everyone laughs except that one person with the confused look. Being meme-oblivious can also cause mass amounts of butthurt, but only a special kind of butthurt that should be avoided by all cost.
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.
Joe: Hey, it's Jim and his girl!
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.