"He's are really smart! He always get high marks in school!"
I'm sure we've all heard that many times. Many of us have said it.
I graduated from high school with an average of 75%. I failed my first year of college. I re-did that year and got straight 'A's. After that I almost consistently got 'A's. All through college and university. In university I only got 3 non-'A's.
What happened? Did I get inherently smarter? Did my I.Q. rise?
I learnt something very important: School is a skill. Like any other skill, some naturally have it, and some people have to work at it. With the right kind of work, and the right amount of work, just about anybody can become good at it. I didn't have the skill from birth. I never worked on it until I got to college. It took a year, but I got better at it.
If school is a skill that can be learned, how can we know if a person is smart?
That's easy. The more they agree with you, the smarter they are.