Though the water running in the fountain be every one's, yet who can doubt, but that in the pitcher is his only who drew it out?

"Drawing is thinking on paper."

The more time I spent on mathematics, the more excited I got.

Your 20s are the perfect time to do a few things that are unusual， weird， bold， risky， unexplainable， crazy， unprofitable， and look nothing like "success". For the rest of your life， these experiences will serve as your muse

The alternation of motion is ever proportional to the motive force impressed; and is made in the direction of the right line in which that force is impressed.

你必须愿意失败，愿意犯错，并不断尝试。