Context

This line is from the poem "Endymion" by John Keats (1818).

For someone who died young, John Keats had a lot say. His poems were often long, epic affairs, and his masterwork "Endymion" is one of the longest and epic-est of them all. He begins it with an appropriately epic meditation on beauty itself, and tells us that true beauty never fades. If Keats lived today, we doubt he'd be a fan of plastic surgery.

Where you've heard it

You've heard this if someone is quoting Romantic poetry to you. A marriage proposal might not be far behind.

Looking for an epic sci-fi series that, like a thing beauty, feels like it goes on forever? Dan Simmons' Hyperion Cantos is heavily inspired by Keats's poetry, and the third installment, Endymion, makes many references to this poem, including a robot with the resurrected consciousness of Keats himself! No, we couldn't make that up if we tried.

Pretentious Factor

If you were to drop this quote at a dinner party, would you get an in-unison "awww" or would everyone roll their eyes and never invite you back? Here it is, on a scale of 1-10.

Anything from Keats is too honest and romantic to be pretentious.