Matthieu Ricard, Buddhist monk with a PhD. in Cellular Genetics taught us «Happiness can be trained» but who found out about this?

Matthieu Ricard, «Happiness can be trained» In the following video Dilgo Khyentse Rhinpoche who was Matthieu Ricard’s spiritual teacher for many years teaches us: «Buddha said «Happiness comes from taming once’s mind» https://www.quora.com/Siddhartha-Gautama-was-born-into-a-wealthy-family-and-yet-he-gave-up-that-lifestyle-to-become-a-monk-Why-do-you-think-he-would-do-this