Existentialism
Existentialism could be defined as the philosophic doctrine that we are all born into an icy-cold universe that is completely indifferent to our well-being, and that we come to be who we are by making life choices for which we and only we are responsible.
Some say this is a pessimistic doctrine, insofar as it implies that there is no external meaning in life. I submit that, in reality, the opposite is the case, in that we all have the opportunity to confer our own meaning on our lives, and that seems much cheerier than having someone or something else do it for me.
Those wishing to read more can check out Sartre, Heidegger, Nietzsche, Kierkegaard, Camus and the rest. Those who wish to listen to more, however, are invited to check out the video below, in which Warren Zevon, who would have celebrated his 73rd birthday today, performs the much-beloved “The Vast Indifference of Heaven.”