George Berkeley’s Perception

The classic rejoinder:

There was a young man who said God,
must think it exceedingly odd
if he finds that the tree
continues to be
when no one’s about in the Quad.

Dear Sir, your astonishment’s odd.
I am always about in the Quad.
And that’s why the tree
continues to be
since observed by, Yours faithfully, God

Has no one, including ourselves, ever perceived God? How do we know?