The mystery of existence is the greatest of all mysteries and the most basic of the big questions.  It is mainly what has kept me an agnostic rather than an atheist.  (It should be acknowledged that regarding Abrahamic concepts of God I’m more of an atheist.)  The immensity of the universe (or a multiverse cosmos) is incredible; impossible to fathom.  Thinking about this sometimes makes me wonder if perhaps almost anything might be possible. However, it doesn’t make me a believer.  I‘m in agreement with physicist Richard Feynman who once said in an interview:  “I can live with doubt and uncertainty.  I think it’s much more interesting to live NOT knowing than to have answers which might be wrong.”  I truly don’t know how there happens to be any existence.