The promise of youth is expressed by the phrases "fruit without flowers", "flowers without fruit", "manhood" and "real excellence".
Explanation:
The author talks about no fruit without flower that is there is no result if there is no hard work done by the person and in order to get the flowers in the outcome, there has to be some hard work to be done.
Author also talks about thousand arrows shot from the same point which represent some will get the target and some will not get target. The flight of all the arrows would be different. Similarly some people will achieve the target and some won't.
