Before age 24， we believe that our happiest years are yet to come； over 30， we believe that they're behind us. A National Health Survey agrees： After age 30， we "become more realistic and do not view happiness as a goal in itself. If we maintain our health， achieve professional and emotional goals， then happiness， we feel， will follow".
When are you most creative？ Generally between 30 and 39， but the peak varies with different professions.
Mozart wrote a symphony and four sonatas by age eight， and Mendelssohn composed his best known work A Midsummer Night's Dream at 17， but most of the great music was written by men between 33 and 39.
Though， the peak in most fields comes early — most Nobel prize winners did their top research in their late 20's and 30's —creative people continue to produce quality work throughout their lives. For the "well-conditioned mind"， there is no upper limit.
人生沉浮，看似難以預測。但是，科學家們現在了解到，幾乎所有的人都有一個相當明確的模式。即使度過了一些“黃金時期”，你仍然可以在未來經曆另外的黃金時期。某些重要的黃金時期好像要在生命的後期才能達到巔峰。
你什麽時候最聰明？根據智商測驗的分數，是從18歲到25歲期間。但是，隨著年齡的增長，你會更加明智，經驗更加豐富。
你的思維最敏捷是在20多歲的時候，到了30歲左右，記憶力開始下降，特別是你的數學計算能力降低。但是，你做其他事的智商提高了。例如，你45歲時的詞匯量是你剛從大學畢業時的3倍。到60歲時，你的大腦儲存的信息幾乎是你21歲時的4倍。
根據敏捷和智慧之間的轉化，心理學家提出了一個適用於成年人的概念“成熟商（M.Q.）”。
你什麽時候最快樂？你對自己身體感覺最好的時期是從15歲到24歲。職業感覺最敏銳的時期是從40歲到49歲。