What is the central idea of poem The Brooke Lord Tennyson?

Please provide the name of the poem you're referring to. There is no known poem called "The Brooke Lord Tennyson".

It's possible you're thinking of one of these:

* "The Brook" by Alfred Lord Tennyson: This poem is about a brook that flows through the countryside, observing the changes of seasons and reflecting on the passage of time.

* A poem by Lord Tennyson about a specific Brooke: Tennyson wrote many poems, and it's possible one is about a specific person named Brooke.

To help me understand what you're looking for, please clarify the poem's title or provide more context.