Spoilers for the March 25 episode. It's no wonder that Morgan is due for a vacation on Fear The Walking Dead this year. His troubles are growing on the East coast, and a trip out West might help clear his mind and stop some recurring patterns. Morgan is hallucinating on The Walking Dead, or at the very least being haunted by his past, and the phrase "you know what it is" comes back in a very creepy way — what does that mean?!
In Sunday's episode, Morgan is thrice "visited" by the memory of Gavin, the Savior he almost killed before young Henry stabbed him. "You were supposed to," Gavin says multiple times before repeating, "you know what it is." Morgan is disturbed by this, and starts doing some Eastman exercises in response. What is "it"? Morgan knows, but the audience doesn't. What is he supposed to do, according to this vision? Couldn't Morgan and his demons have picked something less vague as a catchphrase?
Keen fans of The Walking Dead will remember that this isn't the first time "you know what it is" or "you were supposed to" has been of significance to Morgan Jones. In the Season 6 episode "He's Not Here," Morgan repeated "You had the knife. You had the gun. You know you were supposed to." as well as "16 hours and 19 on the floor. You know what it is."
That's the episode where he met Eastman (the man who taught him Eastern philosophy, get it), and learned to to kill infrequently and carry a big stick. Gavin is holding Morgan's stick in the vision — which is either a reference to Eastman or a reference to how Gavin's partner Jared taunted Morgan with his own weapon. Gavin was also, of course, killed with Henry's sharp and pointy version of Morgan's fighting staff.
What do these phrases mean, though? It has stumped fans for seasons. Morgan does like to count, and has never been the most mentally stable person on The Walking Dead. The repeated sentences could be a reference to a memory, or a regret he has. The longer version of "you were supposed to" might hint that Morgan feels as if he should have been the one to kill Gavin himself, rather than young Henry. Reddit user reddittechnica theorized in 2015 that since Rick gave Morgan a gun to kill his zombified wife in the pilot, and he couldn't do it, he feels responsible for his son's death. "You were supposed to" means that he was supposed to step up then, and again now.
What "it" is, on the other hand? Still kind of a mystery. But it's definitely not a nonsense phrase. Morgan knows what the problem is? He knows what the solution is? Hopefully the object of the sentence will be revealed in an upcoming episode.
In general it seems as if Morgan is going back over memories, replaying moments and regrets, and basically losing focus — all while being haunted by the face of a man he didn't even kill. How unfair! Perhaps he's feeling guilty about how his legacy is little baby murderer Henry and not someone more like his mentor, Eastman. That part is understandable.
This is also, possibly, a sign that Morgan hasn't lost all of his humanity yet. Guilt is a good thing, in this scenario. It means that he still cares about others, or wants to. These visions, in all seriousness, are likely setting up his journey for Fear The Walking Dead. It's time for Morgan to move on, and clear that this isn't going to happen if he stays with this group.
As important as Morgan is to Rick, Carol, and the others, his sanity is at stake. These phrases and figures from the past are as good a sign as any that he needs a break before he himself is broken.