In junior high, we learned in literature class the famed piece Yueyang Lou Ji (《岳阳楼记》) by the prominent Song-dynasty literary figure Fan Zhongyan. In it there were two most important sentences that have been quoted by writers and scholars throughout the one thousand years after Fan's era. They were Xian tianxia zhi you er you; hou tianxia zhi le er le (先天下之忧而忧，后天下之乐而乐, literally "Worry before the whole nation do; enjoy after the whole nation have done"), and Bu yi wu xi; bu yi ji bei (不以物喜，不以己悲, literally "Feel no ecstasies for the outer world; feel no sorrows for your inner self").
Back in junior high, I didn't fully understand either of these two sentences. By senior high, I think I already understood the first sentence, to think about state affairs and the future of the country before most everyone does, but I still couldn't bu yi wu xi and bu yi ji bei. Not until this day, I realized that I am now nearly capable of the second level, with myself unmoved by the many happenings, be it agreeable or unfortunate, in life.