Woulda-Coulda-Shoulda by Shell Silverstein

All the Woulda-Coulda-Shouldas
Layin' in the sun,
Talkin' bout the things
They woulda-coulda-shoulda done...
But those Woulda-Coulda-Shouldas
All ran away and hid
From one little did.

Forgotten Language by Shel Silverstein

Once I spoke the language of the flowers,
Once I understood each word the caterpillar said,
Once I smiled in secret at the gossip of the starlings,
And shared a conversation with the housefly
in my bed.
Once I heard and answered all the questions
of the crickets,
And joined the crying of each falling dying
flake of snow,
Once I spoke the language of the flowers. . . .
How did it go?
How did it go? 

There once was a man from Wesser
Whose knowledge became lesser & lesser
It grew so small
Soon he had none at all
And now he's a college professor