It's The Moral Of The Thing Poem by D.M. Barber

i like your hair she tells me
speaking everything but the lie
she describes it as the reason
why she could not stand to die

as she notices its flicker
and its beuty in the light
she relises it's rareness
it's beuty when in sight

she reaches out to touch it
i move away real fast
for looking should be enough
if you really want it to last

something so amazing
should never be abused
for once it has been broken
it can not be reused.

it's not the hair that matters
but the moral of this rhyme
for everything must die
as it grows older over time