Use Just Twenty Lines

They said to use just 20 lines
And compose a poem to withstand time.
Only 18 now, What can I do?
To make a poem just for you
16 lines is not a lot
for telling you all the words I’ve got.
With only 14 lines to play
I must think of, What-to-say.
12 short lines, No-More, No–Less.
I must search for my-very- best.
Just 10 lines now till the end
And all I can do is show a grin
8 little lines will be enough.
To tell you some, of all my stuff
6 short lines with which to say
I hope today is your special day
These last 4 lines are just for fun
And bring a close to what I've begun
2 last lines to help close the gap
I have had enough of all this crap.