Okay, I understand, I thought you were posting about something recently said, not the Original Topic.
In that case, I'd like to agree that saying 'the Universe exists' should be axiomatic. It is a self-truth, an identity. That is, by doing something, you prove that you exist, or at least that you percieve that you are doing something, and even then, you are doing something by perceiving, now, if you are capable of doing something, then you exist. If you exist, you either
a.) are everything
or
b.) are a part of something greater than yourself
Now, if you are everything, you are by definition the Universe.
If you are a part of something greater, than that greater thing is the Universe.