Nietzsche is the philosopher who believed that the people who desire to live a life with no worries are mediocre people that do not give greater meaning to life.

Happiness to him is an ephemeral and fleeting condition that could end at any possible moment. He believed that contentment can only be found with having vital strength and a fighting spirit in order to overcome life's adversities.

Jose Ortega y Gasset believed that happiness is found when the projected life and the effective life coincide with each other. This translates to "the paths of what we want to be and what we truly converge."

He believed that everyone has the desire to be happy and each person defines their own reality where they look for something that would satisfy and gratify them completely.

Zizek believes that true happiness is merely a matter of opinion not of truth.

To him, satisfaction and contentment are products that are born under capitalistic values where it promises eternal satisfaction through consumption. Unbeknownst to us, dissatisfaction reigns over because no one knows what they truly want.

The unconscious reality is that when we try to achieve something that will make us "invariably happy" is just another thing that will leave us further dissatisfied.