You can't go in. Practice.
3 seconds sound clip from the Crippled Kung Fu Boxer movie soundboard.
You can hear this line at 00:30:22.633 in the DVD version of the movie.
Quote context
[...]
- Your father told us to bring you food.
- I guess this must be Mr. Hsiao, isn't that right? Mr. Fu said you were a kung fu expert.
- Oh, they're, they're part of my family, this is Long Chun, and he's Long Chin.
- How are you, won't you come inside?
- Teacher, if you keep on at me, I'm gonna crack up, you're gonna kill me.
- Hmm, whoever told you kung fu was easy. Get up. Try your hardest to make me fall down.
[...]