look back or look ahead

From five months, I turned forty
So I look back or look ahead
Back to what I was or ahead to what I'll be
But not too far because then I'd be dead
I decided to look back then travel ahead
Exploring my most pivotal years
Remembering things people had said
Examining my deepest fears
if my memory still exist 
Childhood, years of innocence and wonder
Everything to a child's eyes is new
Til one day, innocence is torn asunder
As surely as the sky will be blue
Teenage years, a sense of immortality
At such an age death is not even imagined
Doing everything with such youthful vitality
Not knowing the end is already predestined
Twenties and Thirties maturity is reached
And things just seem to fall into place
Is remembered in the look on a child's face
In your Forties attaining middle age
Deciding that maturity looks good on you
Graying hair, against which you don't rage

You feel it's distinguished, how very true