Reader's question:

Going to bed early is key to getting enough sleep and helping adolescents feel on top of the world, a new study reported. Could you explain “on top of the world”?

My comments:

If you’re on top of the world, say, standing atop of Mount Everest, you feel high.

Obviously. Metaphorically speaking, when people say they feel they’re on top of the world, they feel extremely good of themselves – everything is going well for them.

In the above example, when doctors say going to bed early helps youngsters feel on top of the world, they’re merely saying sufficient sleep make they refreshed, energetic, rejuvenated…

And raring to go, ready to take on the whole world.

Related stories:

Button your lip

Pass the buck

Fire sale

Nuts and bolts

Across the board

Be in someone’s shoes

In that vein

The devil you know…

Right out of the gate

Leap-frog

Up the ante

loose ends

Nose-bleed section

Off the rails

Keeping up with the Jones's

Benefits package

Closed-door talk

March Madness

On-again,off-again

Go to Zhang Xin's column

本文仅代表作者本人观点，与本网立场无关。欢迎大家讨论学术问题，尊重他人，禁止人身攻击和发布一切违反国家现行法律法规的内容。

Zhang Xin has been with China Daily since 1988, when he graduated from Beijing Foreign Studies University. Write him at: zhangxin@chinadaily.com.cn, or raise a question for potential use in a future column.