Philosophies of life are a product of culture, and cultures come and go.

“Every time I find the meaning of life, they change it.”

“Do every act of your life as though it were the very last act of your life.”

“Live as if you were living a second time, and as though you had acted wrongly the first time.”

“Existence precedes essence.”

“Do not spoil what you have by desiring what you have not; remember that what you now have was once among the things you only hoped for.”