Though he thought it through, it still failed. Check your spelling of KS3 words beginning at th.
"As a single footstep will not make a path on the earth, so a single thought will not make a pathway in the mind. To make a deep physical path, we walk again and again. To make a deep mental path, we must think over and over the kind of thoughts we wish to dominate our lives." - Henry David Thoreau.
Thoreau's description of creating mental pathways refers to the way in which habits are developed. These can be physical habits, such as those which create a path on the ground, and mental habits, such as those which shape a person's view of the world.
Thoreau surely did not have spelling in mind when he compared the physical and the mental formation of paths, but it is true that spelling habits develop through repetition, too. This is why practice really does help a person become a confident speller. It is equally true that repeatedly misspelling words becomes a habit which is difficult to break. Try to develop good habits from the start when you learn a new word by paying attention to how it is spelled.