Youth is not a time of life; it is a state of mind.
青春不是年华，而是心境；
It is not a matter of rosy cheeks, red lips and supple knees.
青春不是桃面、丹唇、柔膝;
It is a matter of the will, a quality of the imagination, vigor of the emotions;
而是深沉的意志、宏伟的想象、炽热的感情；
It is the freshness of the deep spring of life.
青春是生命的深泉在涌流。
Youth means a temperamental predominance of courage over timidity.
青春气贯长虹，勇锐盖过怯弱，
of the appetite for adventure over the love of ease.
进去压倒苟安，如此锐气，
This often exits in a man of 60, more than a boy of 20.
二十后生有之，六旬男子则更多见。
nobody grows merely by the number of years;we grow old by deserting our ideas.
年年有加，并非垂老；理想丢弃，方堕暮年。
Years may wrinkle the skin, but to give up enthusiasm wrinkles the soul.
岁月悠悠，衰微只及肌肤；热忱抛却，颓唐必至灵魂。
Worry, fear, self-distrust1 bows the heart and turns the spirit back to dust.
烦忧、惶恐、丧失自信，定使心灵扭曲，意气如灰。
Whether 60 or 16, there is in every human being's heart the lure of wonders,
无论年届花甲，抑或二八芳龄，心中皆有生命之欢乐，奇迹之诱惑。
the unfailing childlike appetite of what's next and the joy of the game of living.
孩童般天真久盛不衰。
In the center of your heart and my heart there is a wireless station;
人人心中皆有一台天线，
so long as it receives messages of beauty, hope, cheer, courage and power from men and from infinite,
只要你从天上人间接受美好、希望、欢乐、勇气和力量的信号，
so long as you are young.
你就青春永驻，风华常存。
When the aerials are down, and your spirit is covered with the snows of cynicism and the ice of pessimism,
一旦天线倒塌，锐气被冰雪覆盖，玩世不恭、自暴自弃油然而生，
then you've grown old, even at 20, but as long as your aerials are up,
几十年方二十，实已垂老矣；
to catch waves of optimism, there's hope you may die young at 80.
只要虚怀若谷，让喜悦、达观、仁爱充盈其间，你就有望在八十高龄告别尘寰时仍觉年轻。
拓展资料：
《青春》是塞缪尔·厄尔曼的著名散文。
他(1840.4.13-1924.3.21)是一名生于德国的美国作家。儿时随家人移居美利坚，参加过南北战争，之后定居伯明翰，经营五金杂货，年逾70开始写作。
所谓青春，并不是人生的某个阶段，而是一种心态。卓越的创造力、坚强的意志、艳阳般的热情、毫不退缩的进取心以及舍弃安逸的冒险心，都是青春心态的表征。
松下电器的创始人松下幸之助几十年来也把《青春》当作他的座右铭。
参考资料：塞缪尔·厄尔曼_百度百科