I didn't say that nothing we do matters. Quite to the contrary -- all our actions shape the universe even if that change is miniscule. What does not matter is how we look at things and how we label them, i.e. what standpoint we assume. Then again, in the overall scheme truly nothing matters, because the mattering of actions is, too, just a standpoint.

As I said many times before, you can observe it in the way humans live -- most are selfish, some are selfless (for selfish reasons), some are (probably) unconditionally selfless. It really does not matter what each of these people do -- universe is here, humming as it always was. But what is undeniable are the consequences of actions.

So the questions should be rephrased as, "Why cause pain?", "Why feel disturbed?", "How to know which actions have what consequences?", and "What actually means good and evil?" Also, you should probably ask, "Where does nature end?"

In other words, people feel separated and dual because they look at universe that way. Nothing wrong with that, but there are other ways of existence. I'm for trying them all.