* When Foon is trying to become Master Yen's apprenticce, and Yen tries to discourage him by saying "What's the use of being a kung fu expert? Can't make a living.". At this point, Yen has just defeated a capable, renowned warrior, but at the end of the day he's on the street starving in the pouring rain. He has a set of impressive skills that probably took a lifetime to master, but his abilities seem increasingly obsolete in the society he is living in. It makes his eventual turn towards villainy all the more tragic. He wasn't really a bad man, which you can see when he practically begs Foon not to desert, but he considers himself backed into a corned such that working with the gangsters is his only respectable option.
** His heartbreaking demise at the gunfire of the American mercenaries really hits home the tragedy of westernization in China harder than anything committed to celluloid before or since.