My DH, "got it" the day we had a 5 & 6 yo old over for a play date with our DD, who was barely 5 at the time.

We assumed Battleship would be a fun easy game for Kindergarteners because our DD easily learned it at 4.
But after 30min of trying to teach DDs friends the concept, my husband gave up.
Later on he admitted that "maybe she is a little different after all."