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"The essence of mathematics lies in its freedom."

We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win, and the others, too.

Safety isn't just a policy; it's a culture we must live every day.

你唯一應該試圖超越的人就是昨天的自己。

The consistency of your endeavors (exercise， companionship， work) is more important than the quantity. Nothing beats small things done every day， which is way more important than what you do occasionally.