吾十有五，而志于学。三十而立。四十而不惑。五十而知天命。六十而耳顺。七十而从心所欲，不逾矩。------《论语·为政》孔丘（約前551年－約前479年）
At age 15, studying hard;
At age 30, standing on my feet, achieved my goal;
At age 40, no confusion;
At age 50, accepting my fate;
At age 60, knowing the true meaning that other people's say;
At age 70, following my hard and relaxing within the rule.
----Lunyun. Politics， by Kong Qiu ( B.C. 551-B.C. 479)