Birthday poem

So it's your fortieth birthday;
Four decades have gone and passed.
They say when you get older,
Time goes twice as fast.

I wouldn't know,of course,
Since i am still  quite young,
But for you,the music is over;
Your last song has been sung.

You are just over the hill at forty;
you went down without a fight.
Time rushes on,and soon
That "hill"will be out of sight!

Happy birthday anyway!