My friend Domino has minor brain damage from an old head injury.  It’s only when he’s stressed or tired that he notices it.  His damage was to the frontal lobe and left temporal lobe.  The result is mostly that there’s a time delay between info input and info processing.  How he describes it is like with schedules and calendars and directions and maps, he’s very visual.  If you write it down for him, he understands it immediately.  If you tell him, he has to translate it into written form before he can identify it, meaning, he has to write it down before he even grok what you’re saying.  If I mention a new place to meet, he can be thrown into a frenzy until he Googles the address and sees the map and gets a feel for the location before considering whether that’s a viable place to meet.  Just the mention of a new name or location when he’s stressed or needs sleep can befuddle him.   Knowing this ahead of time makes me more careful with him.  But I can still catch him on the rare day and forget and start calling out directions and landmarks to him on the phone and then not be surprised when he just hangs up on me due to the overload.   I’ll learn.