We are like butterflies who flutter for a day and think it is forever.
— Carl Sagan
It is said that your life flashes before your eyes just before you die. That is true, it's called Life.
— Terry Pratchett
When you were born you were crying and everyone else was smiling. Live your life so at the end, you're the one who is smiling and everyone else is crying.
— Emerson

Our chief want is someone who will inspire us to be what we know we could be.
— La Rochefoucauld
I criticize by creation, not by finding fault.
— Cicero
At bottom I abhor all those moralities which say: "Do not do this! Renounce! Overcome yourself!" But I am well disposed toward those moralities which goad me to do something and do it again, from morning till evening, and then to dream of it at night, and to think of nothing except doing this well, as well as I alone can do it. When one lives like that, one thing after another that simply does not belong to such a life drops off. Without hatred or aversion one sees this take its leave today and that tomorrow, like yellow leaves that any slight stirring of the air takes off a tree. He may not even notice that it takes its leave; for his eye is riveted to his goal – forward, not sideward, backward, downward. What we do should determine what we forego; by doing we forego – that is how I like it, that is my placitum. But I do not wish to strive with open eyes for my own impoverishment; I do not like negative virtues – virtues whose very essence it is to negate and deny oneself something.
— Nietzsche

The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner, how frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. Our posturings, our imagined self-importance, the delusion that we have some privileged position in the Universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves.
— Carl Sagan
So Fermi said, “Well... there is the remote possibility that neutrons may be emitted in the fission of uranium and then of course perhaps a chain reaction can be made.” Rabi said, “What do you mean by ‘remote possibility’?” and Fermi said, “Well, ten per cent.” Rabi said, “Ten per cent is not a remote possibility if it means that we may die of it. If I have pneumonia and the doctor tells me that there is a remote possibility that I might die, and it’s ten percent, I get excited about it.
— Richard Rhodes, The Making of the Atomic Bomb
The best way to predict the future is to create it.
— Peter Drucker
Those who have a 'why' to live, can bear with almost any 'how'.
— Viktor Frankl