One of my sibs deliberately did not follow directions in K, to relieve mind-numbing boredom.
I've also seen some highly-conceptual children have odd gaps in rote memory tasks, like learning the names of things (colors, shapes) and people. Note that learning the name of a triangle around age 4 is entirely normal. That's not a conceptual task. Was he able to sort shapes, or place them in form puzzles, at an earlier age? (Which would indicate that he understood the shape of a triangle conceptually, and it's visual-spatial characteristics, even if he didn't know the arbitrary label we use for it.)
