该句通过对比现在与过去的感受形成哲理表达。
Youth is a brief dream; once you wake up, it has already vanished without a trace. — Shakespeare
Youth is like early spring, like the morning sun, like the budding of a hundred flowers, like a new blade emerging from a whetstone; it is the most precious period of life. To society, youth is like fresh and lively cells in a body. — Chen Duxiu
Youth is not a period of life, but a state of mind. — S.E. Schuman
The fantasies of youth are both passionate and lovely. — Joachim Gaspara
The days of youth pass in the blink of an eye. — Horace
No one feels youth passing, but everyone feels that youth has passed. — Seneca
If youth has any flaw, it is that it passes too quickly. — Robert Lowell
The important thing is not to waste your youth and vitality. — Chekhov
Some people are only half perfect when they are young, while the other half is foolish. The only flaw of youth is that one grows up too quickly. When we have youth, we must use it every day, otherwise, it will soon disappear. — Anonymous
青春时代是一个短暂的美梦，当你醒来时，它早已消失得无影无踪了。——莎士比亚
青春如初春，如朝日，如百卉之萌动，如利刃之新发于硎，人生最宝贵之时期也。青年之于社会，犹新鲜活泼细胞之在身。——陈独秀
青春并不是指生命的某个时期，而是指一种精神状态。——塞·厄尔曼
青春的幻想既狂热又可爱。——约肖特豪斯
青春时光转眼即逝。——贺拉斯
没有人会察觉到青春正在消逝，但任何人都会察觉到青春已经消逝。——小塞涅卡
如果说青春有缺点，那就是它消逝得太快。——拉·洛威尔
重要的是不要浪费你的青春与元气。——契诃夫
有些人在小时候只有一半的完美，另一半则是愚蠢。年轻唯一的遗憾是成长得太快。青春，当我们拥有它时，一定要每天尽情使用，否则它很快就会消失。——佚名