We are in the heyday of youth.
Everyone remembers the happy days of his youth as his halcyon days.
Do not idle away your youth or you will regret it later.
You may have good reason to think that your youth is over.
I regret having idled away my youth.
Youth comes but once in life.
That very tune reminded me of my adolescence.
Everyone remembers the happy days of youth as his halcyon days.
In the course of our conversation, he referred to his youth.
It's no use thinking about one's lost youth.