In the poem "When I have Fears," the speaker categorically lists particular fears that he has:
1. Fear of dying before he has written all that he can.
The speaker describes this fear at the very beginning of the poem in reference to objects: pen, brain, and books. He describes his brain as "teeming," suggesting that it is full of unwritten ideas and thoughts that Keats wishes to have a chance to express.
2. Fear that he may never live long enough to trace the shadows of the stars
This next fear builds upon the first, as the speaker ruminates on the beauty of the night sky, wishfully thinking that he wants to have plenty of opportunities to view "huge cloudy symbols of high romance." He connects the beauty of the stars to being in love, letting the reader know that he wishes to experience and feel both. The "huge cloudy symbols of high romance" also speak to his previous desire to write and express himself, so the reader could also interpret this phrase as reflecting his wishes to communicate that passion into romantic poetry.
3.Fear that he may never look upon the fairness of his lover
All of Keat's fears connect like links to a chain; previously he longed for writing, the beauty of the night sky and romance, and now he specifically addresses being with his loved one, whom he describes as "a fair creature of an hour." She may only be a passing beauty, but he fears not ever seeing her again. She has inspired him with her fleeting presence.
4. Fear of being absolutely alone.
The speaker also couples this fear with the fear that fame and love may be worthless. This dark ending concludes Keats' poem in a tone of anxiety and also bitterness.
"When I Have Fears" comes across to the reader as an extremely insightful and introspective look at the mind of the young poet.