Thomas Wolfe's "Man's Youth"

Man's youth is a wonderful thing; it is so full of anguish and of magic and he never comes to know it as it is, until it has gone from him forever.

It is the thing he cannot bear to lose, it is the thing whose passing he watches with infinite sorrow and regret, it is the thing whose loss he must lament forever, it is the thing whose loss he really welcomes with a sad and secret joy, the thing would never willingly relive again, could it be restored to him by any magic.