In a discussion around a subject like the one in this thread, the reasoning about facts, theories, and the reflections and analysis around those, will lead to an interesting development of the discussion.

That I/you/we just "do" is not adding anything, it's like asking why do we love, a thing, a person, etc. The answer can be "because it feels good", OR we can instead find out more about the psychological and physical things that brings us to that mental state, and analyze them in order to find out how it works... In a bigger picture...