Another random headcanon: John forgetting which information was given to him by the eye and which he was just told. So he randomly drops information he shouldn’t know in casual conversations like
John: hey remember the guy you hated from your old place you used to work at, the express delivery place? I think his name was Tom?
Martin: yeah- wait. I never told you about Tom nor my previous workplace.
John: oh I guess that one was the eye. Well anyways apparently he got fired so he decided to set on fire the car of the ceo.
Martin: Hah, nice.
Can you imagine how hard it is for Martin to make a surprise for John? XD
John: Martin, are we going to use that film projector you bought in the morning to watch film tonight?
Martin: JOHN!!!! THAT WAS SUPPOSED TO BE A BIRTHDAY PRESENT!!!!