Altruism, having more consideration for others, is the only unifying concept that allows us to answer the main challenges of the 21st century and to reconcile the demands of the economy in the short term, the search for happiness in the mid-term, and respect for the environment and for future generations in the long term. Research in the neurosciences that has shown that any form of training induces a restructuring in the brain, at both the functional and structural levels. This is also what happens when one trains in developing altruistic love, compassion and other fundamental human qualities which contribute to happiness. To build a better world together, we need to understand that altruism is not a luxury, but a necessity. In essence, we must transform ourselves to flourish in life and better be at the service of society.