The most successful learning strategy is trial-and-error. It's the strategy that's built into us: it's how we learn to walk and talk. It's how we learn to stack block on top of each other to build tower that doesn't fall. When blocks fall, we learn our last stacking strategy won't work in the future, so we try something else. In a deeply visceral way, we learn what works and what doesn't.
A core part of trial and error is failure. To learn from trial-and-error, you must go through many iterations of trying, failing, recovering from that failure, and mining it for useful information, so that your next trial will be a little bit smarter.
If a baby was cowed by failure, he would never learn to walk. He would give up long before he could stand and spend the rest of his life crawling. So we're shipped from the factory with the ability to play past failure.
Somewhere along time line, many of us lose this skill. It gets killed by parents (who are "very disappointed" in us when we fail), peers (who laugh at us when we fail), but mostly by school, which teaches us to stop failing. We wind up as adults who are terrified of failing and who do the best we can to arrange our lives so that we never fail. We learn to avoid situations in which we're likely to fail. Which means our opportunities for growth are extremely limited. School teaches us how not to grow. It teaches us how to coast. And for the most part, our cultures are rigged to reward coasters.
In most schools, an F is shameful. The goal is to learn how to get As with the smallest effort possible, so that you can coast. There's no impetus to not do this. Few teachers say, "You've gotten four As in a row, so clearly I'm not challenging you enough. I'm going to keep making your assignments harder until you get some Fs, and then I'm going to help you learn from them."
The top students know that they can get As in their sleep. They have mastered the system and, from that point on, rarely learn anything new. And what they learned before was "how to master the system." Many people remember almost nothing they learned in school, but they're still proud of their 10.0 averages.
The students who struggle learn how to avoid struggling. They learn "I'm not a Math person" or "I'm not a creative type." They learn what sort of subjects to avoid, so that they don't have to go on experiencing failure. Someone who has been taught "I'm not a math person" will generally decide that in his teens and never reconsider it. At 50, he'll still be "not a math person." Math, for him, is associated with failure, which he's learned to avoid.
Most students think of Fs as punishment, which means failure -- the best learning tool there is -- is a punishment as far as they're concerned. Our entire educational system is rigged to frame Fs this way.