Life.

It starts.
It ends.

It's the bit between
That depends
On the vagaries
Of the lottery
Bound up in the verb to be.

Some with an average life expectancy of many years
Barely having time to take a breath
Before being taught their first and fatal lesson
By the chalk white claws and incisors
Of the jungle blackboard's hunter-teachers.

Mayflies draw the shortest straw:
Just a single, solitary day,
And then only if they keep well out
Of the Rainbow and Brown Trout's way.
Dragonflies don't fare that much better
If the truth be told,
Four or five glory-filled days at most:
Enough to mate – never to be old.

Most birds manage to see the seasons turn
Once, twice or more
Provided they aren't taken
By heatwave or winter's ice-white jaw.
And Man's Best Friend is thought generally lucky
If he gets to see the other side of a decade
Even with the benefit of the comforts of home
And all the veterinary advances made.

Man.
Theoretically three score years and ten,
But really just the time between 'now' and 'then'.

Tony Jolley

http://www.poemhunter.com/poem/between-now-and-then/