叶公问子路：孔子是怎样的人，子路不回答。孔子说：“你怎么不说：他这个人啊，发愤学习就忘记吃饭，高兴起来就忘记了忧愁，不知道快要变老了等等？”

Success is 1% inspiration and 99% perspiration.

At that age， I'd take any excuse to make estimates and do minor arithmetic. I'd calculate our gas mileage -- figure out useless statistics on things like grocery spending. I'd been hearing an ad campaign about smoking. I can't remember the details， but basically the ad said， every puff of a cigarette takes some number of minutes off of your life: I think it might have been two minutes per puff. At any rate， I decided to do the math for my grandmother. I estimated the number of cigarettes per days， estimated the number of puffs per cigarette and so on. When I was satisfied that I'd come up with a reasonable number， I poked my head into the front of the car， tapped my grandmother on the shoulder， and proudly proclaimed， "At two minutes per puff， you've taken nine years off your life！"