This is the first video released by a project that I admire very much, called Study Buddhism. The project is coordinated by prof. Alexander Berzin (many times translator of The Dalai Lama and a very profound connaisseur of Tibetan Buddism) with whom I had the privilege to talk a few times. In February this year I also had the privilege to organize an event with him and one of his colleagues and it was a very enlightening, but at the same time natural and warm, experience.
The short video above dwells on 3 main principles that you need to understand before starting to train your mind for happiness: interdependence (everything is related to everything), impermanence (everything will cease to exist, eventually) and compassion (everybody has his own set of troubles and fighting his own battles).
It's simple advice but it just works.