Rejoice, O young man, in thy youth; and let thy heart cheer thee in the days of thy youth, and walk in the ways of thine heart, and in the sight of thine eyes: but know thou, that for all these things God will bring thee into judgment.
Therefore remove sorrow from thy heart, and put away evil from thy flesh: for childhood and youth are vanity.
There is a Pennsylvania Dutch saying that comes to mind: “Too soon old, too late smart.”
I’m afraid most of us tend to rejoice in our youth after it has already faded, and the signs of age begin to set in. Only then do we realize what a blessing it is to have strong muscles and bones; to be full of energy, to be able to do a full day’s hard work and still enjoy family and friends in the evening. To take all that for granted is not surprising, because, barring some disease or injury, it’s all just there, day after day.
Another piece of advice to the young, along with rejoicing in their youth, is to remember that all our choices, all our behaviors, will be brought into judgment by God. Sometimes, we make really dumb decisions when we’re young. It is easy, in the days of our strength and energy, to believe we have all the answers. Sinful choices we make, if they go unrepented and unconfessed, will be brought to our account when we meet God. So be wise in your choices, and shun companions who would lead you into things you know are not honoring to the Lord.
Verse 10 admonishes the young to not be sorrowful, and to avoid evil, because these things are vanity.
Several commentators believe that these two verses would be better attached to Chapter 12, because that chapter is the beginning of specific teaching on living life under the hand of God, and not from the human perspective. It makes sense to me.