Mysterious Title Poem by I, Mongoose

First line of bottomless poem
Second comes in and rhymes the first
Third introduces a new idea
And the Fourth makes it burst.

Fifth slightly changed in tone
Sixth opens the vocabulary cabinet
Seventh just is here to fill space
Eight has subtly profound phrasing

Ninth seems like you've heard it somewhere
Tenth is mostly unintelligible
Eleventh is the beginning of the end
Twelfth might be the final line

Thirteenth makes a broad statement
And Fourteenth closes it with a poignant particular.