Why do we exist? Is incoherent.
I was tempted to write an essay, but I don't feel like going to the trouble of it with an entertainment system. Fortunately, it doesn't require one. This is very simple.
Before you can ask why, you must at least know what. Where, when, how, and even who (what, personified) can be helpful, but aren't inherently necessary, yet they can be depending on the why question.
To ask: Why is the sky blue?; you must first know that the sky can be blue at various times. If you don't know that the sky is blue, then the question is assuming that the sky is blue. In fact, the sky is not blue, it is black. But it appears to be blue to our eyes, and that is sufficient to ask why it is blue.
Life exists. We know it does. But we DON'T know exactly WHAT life is. 100,000 years of human history, and we still don't have a definition that fits all life, and only life. How then, can anyone ask why, when they don't even know what?
Once-Proud Canadian, Enlightened Atheist, Gaming God.