I was thinking a little more about this post, and the comments people added, and I realized something I think is important that none of us mentioned.
I think Chesterton turned out OK because he had parents at home who loved him and stimulated his mind. So that even if he wasn't getting that at school, even if they all thought he was a dunce there in the school environment, at least at home, he was shining. He was brilliant. His parents treated him as if he had a good mind. They carried on nightly dinner table discussions. Gilbert and Cecil carried on lengthy debates and discussions. Mr. Chesterton read to them, did puppet theater with them, and, with his ever curious mind, was always tinkering with some new project of his own: Edward Chesterton wrote books, illustrated them, did photography (think: back then, photography wasn't the hobby it is today! He had a darkroom at home and everything), and his office was filled with every kind of invention.
Chesterton's mother adored him, and, like Edison's mother, believed in him even when the school didn't recognize his genius.
I think this home life is what saved Chesterton during his school years. And that, I believe is the difference between then and now. Now, if you have a child like Chesterton come through the school system, will he survive? There are precious few parents who engage with the children at home anymore. It's almost a relic of the past.
However, some children still manage. They discover, on their own, great writers or inventors or come upon something or someone that makes a difference in their lives.
Anyway, I just wanted to discuss the "home factor" in Chesterton's education.