One of the most famous quotes of Pythagoras.

Georgios F. Giotopoulos is the Headmaster of Junior High School of Saravali, Patras, Greece. He has 25 years' experience as an adult trainer in the field of vocational training. His interests concern transformative learning and especially transformative learning through aesthetic experience, vocational training, adult education, education management, and teachers’ evaluation. https://eap.academia.edu/GeorgeGiotopoulos https://www.researchgate.net/profile/Georgios_Giotopoulos2