Tell me, Why?

I read this poem, [in “Teaching Children Sensitivity” by Lina and Richard Eyre] and liked it so much that I am posting it on my blog. There is a question in my mind which I have put at the end. Can you help me find the answer please?

by Joshua Eyre [Age 10]

Vacation is a bored tiger
getting freed from his nasty cage.
Vacation is a raccoon
freeing itself from
a hunter’s trap.
Vacation is your friend
getting out of jail.
Vacation is a tree
Leaving its leaves and branches
blow free in the cool breeze.
Vacation is playing
my favourite free song
on the piano.

Can somebody tell me why does it resonate so well with a retired person like me?