Despite my nihilistic leanings, I continue to be concerned with the question of an ultimate purpose of existence. Most religious/spiritual people posit theories like “God was lonely,” “the Universe wanted to experience itself,” etc., none of which I find satisfying. Perhaps this all comes down to the problem of consciousness and it’s origins.
The only "reason" for being is what you create for yourself. You don't have any more reason for being than a fly or a blade of grass. The difference is, that we have a mind to think about these things. Reasons are something that humans invent. So we have to come up with our own reasons. Something that satisfies us, and gives us some purpose. Or, we can just say "I'm going to have a good time with it." and that's okay too.