This is one of the most richly imaginative, creative, downright enjoyable movies I've ever seen. I haven't enjoyed myself this much since Pulp Fiction.
It took me a while to figure out who the hero was. First I thought it was the barber guy who got himself constantly smacked about by the landlady. I suppose it's because he looked so dim, he therefore had to be a kung fu master in disguise. I've read some of the other posts, and everyone seems to think the knife scene was the funniest. I didn't expect to come to this movie for a laugh, but the knife scene almost killed me. Luckily it was just me and my friend in the movie theatre, so I could let it all out.
If you go to the movies to free your imagination, then this is the movie for you. Stay away from people who say it's far-fetched and unrealistic. If they want realism, they should go to the laundromat.