Given scene/plot descriptions from movies or TV shows, and given a specific question about the scene, summarize the question into a title

Let me give you an example: At the beginning of the movie Gangs of New York, Priest Vallon tells his son not to wipe the blood of the blade after he's cut himself shaving, saying "The blood stays on the blade". I've watched the movie multiple times, but can never find what the meaning behind that phrase is. Anyone able to shed some light on this?
The answer to this example can be: What's the meaning behind the phrase "The blood stays on the blade"?
Here is why: A person gives a detailed description about a scene from the movie Gangs of New York and asks the meaning of a said phase in the scene. The question is summarized as What's the meaning behind the phrase "The blood stays on the blade"? for easy indexing the next time someone searches for a similar phrase

OK. solve this:
In the movie 'The Social Network', in the scene after Fashmash has been created but the algorithm has not yet been coded, where Eduardo Saverin gets back to the dorm and talks to Mark about how he and Erica broke up, Mark asks him how he already knows and Eduardo responds "it's on your blog". How is it then that even though Eduardo has been on Mark's blog that he is unaware of the fact that Mark has hacked the facebooks for the other houses on campus, or that he's in the process of creating a website to compare women even though Mark has been blogging about his progress?
Answer:
How is Eduardo unaware of the progress on Face Mash?