In the fifth hexagram of the I Ching, Xu, water is up above the sky. Even when clouds are full of rain, we cannon make the rain fall, and this hexagram, Xu, is sometimes translated as "Waiting."
Furthermore, heaven, meaning strength, is combined with water, meaning danger. When one is faced with danger, one carefully times one's actions and while waiting, seeks nourishment in preparation of the work ahead.
Youth requires nourishment and time to grow, and that requires patience and waiting. But patience is usually an asset of old age, not of youth, and it may take a lifetime to master the art of waiting.