Teachers what 'clicked' about a pupil after meeting their parents?(r/AskReddit)

Student Teaching for high school seniors and juniors I had this guy that was a "shady 80", no specific problems just very low intelligence. But this guy worked his ass off. Never a late assignment, did all extra credit that was offered (usually extra credit is done by those who don't need it and ignored by those who do need it), made flash cards for like every test and quiz even though I never said to. Model student, just had low test scores. If it was an assignment that could be done with time and effort, he did it, unfortunately tests aren't like that and that's where he had the most problems.
Back To School Night comes along and I meet his dad, an NCO in the Marines. Curteous, well spoken, and completely knowledgeable about all of his son's up coming assignments and grades.