The ups and downs of life may seem to have no predictable plan. But scientists now know there are very definite patterns that almost all people share.
When are you smartest? From 18-25, according to I.Q. scores; but you‘ re wiser and more experienced with increasing age.
You’re sharpest in your 20’ s ; around 30, memory begins to decline, particularly your ability to perform mathematical computations. But your I.Q. for other tasks climbs. Your vocabulary at age 45, for example is there times as great as when you graduated from collage. At 60, your brain possesses almost four times as much information as it did at age.
When are you happiest? You have the best physical sense of yourself from 15 to 24; the best professional sense from 40-49.
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 “because 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 know 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, creative people continue to produce quality work throughout their lives. For the “well-conditioned mind”, there is no upper limit.
麻烦翻译为中文谢谢 要求通顺

本人不才 来补充下面的

24岁前，我们相信我们最快乐的岁月将会来临：30以后，我却认为这些岁月已经离我们而去。一项国家健康调查表明：30岁后，由于我们变的更加现实，没有将已有的幸福视为幸福本身。如果我们能保持健康，在职业和情感方面都取得成果，我们的幸福将会随之而来
你在什么时候最具有创造力？大概在30到39岁之间，不过创造力的峰值会由于不同的职业而变化
莫扎特8岁时写了一首交响曲和四首奏鸣曲，门德尔松在十七岁时创作出了他最著名的作品“仲夏夜之梦”。 但大多伟大的音乐作品是在作者33到39岁间创作的。虽然峰值在大多领域出现比较早，但那些有创造力的人，他们整个人生都在继续创作优秀作品。对于“条件良好的大脑”来说，创造力是没有极限的。