They did tell me this when I was an teenager: "You're a smart kid, but you need to put in more effort".
I tried putting effort towards school for a while. I figured if I had to play, I may as well win. The problem with treating high school as a game is that it's not fun. Learning the material doesn't get you anything, not even more advanced material to dig into.
For me, digging my teeth into a difficult problem is it's own reward. In high school I wasn't asked to work on difficult problems. Instead I sat in the back of the class, ignored the lecture, worked on whatever I was doing at the time, and coasted through the tests well enough to pass.
Plenty of effort. Plenty of work ethic. Plenty of smarts. Nothing I wanted to work on.
Yeah, they told me too. I wish I'd have seen this paper... though I might not have taken it seriously enough. But still, it's probably better then some old guy who pesters you to work more without any obvious reason.
It's not about effort, it's about self-control. If you had been able to make yourself work on the class assignments, even if you didn't like them, you would have better grades.
