Lol really though...he teaches him concentration and discipline and meditation. That's why he wins at the end. He approaches the mind before the body.
He teaches him balance to flow with qi, basically. That's also why he has him practice in nature.
In the beginning before he trims the bonsai tree he tells him to close his eyes and breathe and be with the tree, and therefore he can do anything.
He breaks bottles on the truck when those guys are bullying them on the beach, and Daniel says how did you do that? and he says I don't know I've never done it before.
Not a coincidence. It's the entire concept behind the film, from the bonsai tree, to the catching flies with chopsticks, to that incident, to wax on wax off and sand the floor.
I'm not doing it. The Tao is doing it (roughly speaking, I'm not sure if the film is based in Taoism or Buddhism, but it's the same inherent concept or idea).
It's why when you ask Buddhist masters for answers to your problems or what they know that you don't, they laugh at you.
The Karate Kid is pure western orientalism.
Its played for entertainment and does not have a lot of depth, you could as easily attempt to see some deep seated meaning in Big Trouble In Little China, the TV series Kung Fu has more philosophy or culture of a meaningful kind in it because Bruce Lee wanted to import eastern cutlure through the medium and gain it some respect, even at that he was not allowed to appear in the led role and no other oriental actors were either.
The breaking bottles thing in the first movie, followed by breaking ice and blocks in the second movie is pure martial arts contests feats of strength and prowess stunts.
The final film has some spiritual overtones (they visit a monastry) but again its a western superficial portrayal of Zen, which has as much to do with stateside gurus and pop culture as the eastern reality.
The narrative in the first film, to a certain extent each of them, of the fatherless youths who are guided towards self discipline and finally stand up to the bullies could as easily have been set in the wild west with John Wayne as Mr Mayagi but the mythologising of foreign esoteric martial techniques was still strong at that time and adds everything to the movie.
There are some amazing "super karate" books available from before that time which if you contrast with modern day books are a barrel of unintended laughs, with a serious tone they dispense pretty ludicrous ideas about physical and mental feats, single strike immobilising blows, that kind of thing, with little or no attention to health and safety, liability or authentication as being from cultures or contexts which confer them with any legitimacy or tradition.
You could as easily say that Quantum Leap was The Tao as the Karate Kid.
Its a great movie though, loved it growing up and loved all that esoteric eastern faddism.