Universal ponderings?

When did I go from
Being a pain in my parents' ass
To having a pain in my own?
Few things so beautifully illustrate
The passage of time
In my life as
To go from amiable child
To rebellious teen,
And from rebellious teen
To befuddled adult,
Then, finally,
To this increasingly creaky
Older person
In middle middle age;
I look back and despair,
Where did the time go?
What legacy will I
Be leaving behind?
I've never married,
Never had children,
Never had any career
To speak of,
So what has been the point
Of my existence?
While looking ahead
And seeing the vast possibilies
Remaining in
My future's blankness,
I ruminate on the past.
Perhaps I have left
Some sweetness
In the memories of my friends,
And some hope in the hearts
Of the children I've sponsored;
Perhaps I've given good lives
To the pets that have graced
My own,
And, maybe, just maybe,
I've left only footprints
And no carnage
In my wake.
Can we really ask so much more
In each of our lives?
Ambition is all well
And good,
And should not be underestimated
In its power
To improve one's lot,
But, in the end,
What will we really be leaving behind
When our time finally comes?