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，看似难以预测。但是，科学家们现在了解到，几乎所有的人都有一个相当明确的模式。即使度过了一些“黄金时期”，你仍然可以在未来经历另外的黄金时期。某些重要的黄金时期好像要在生命的后期才能达到巅峰。
你什么时候最聪明？根据智商测验的分数，是从18岁到25岁期间。但是，随着年龄的增长，你会更加明智，经验更加丰富。
你的思维最敏捷是在20多岁的时候，到了30岁左右，记忆力开始下降，特别是你的数学计算能力降低。但是，你做其他事的智商提高了。例如，你45岁时的词汇量是你刚从大学毕业时的3倍。到60岁时，你的大脑储存的信息几乎是你21岁时的4倍。
根据敏捷和智慧之间的转化，心理学家提出了一个适用于成年人的概念“成熟商（M.Q.）”。
你什么时候最快乐？你对自己身体感觉最好的时期是从15岁到24岁。职业感觉最敏锐的时期是从40岁到49岁。