It is the most common way of explaining an aspect of the relationship between Atman (the individual self) and Brahman (Universal Self) in Advaita Vedanta school of Hinduism. https://www.indianetzone.com/38/ayam_atma_brahma.htm

Sure! But credit where credit is due: I didn't invent this but got it from Thich Nhat Hanh, so it's a Zen Buddhism philosophy.

This story for me made the click of how Zen Buddhism looks at the world.

I love Thich Nhat Hanh as well! I didn't realize this was directly from him! Thank you!