The book “As A Man Thinketh” by James Allen contains the statement:

Mind is the Master power that moulds and makes,
And Man is Mind, and evermore he takes
The tool of Thought, and, shaping what he wills,
Brings forth a thousand joys, a thousand ills: —
He thinks in secret, and it comes to pass:
Environment is but his looking-glass.

I love those last words, “Environment is but his looking-glass”....