A series of letters written by a teenage WB Yeats, in which he confessed of his poems that there were "none that I am at all satisfied with", showed his doubt at his literary prowess.
The seven letters include six addressed to Ethel Veasey and one to her brother, Harley Cyril Veasey, and were sent between 1883 and 1885.
Yeats met Cyril when they were both students at the Godolphin School in Hammersmith in England.
The letters, which were sold for more than £47,000 (€53,000) at an auction in London on Tuesday, give a glimpse into the early stages of his career.
The first letters show his ambitions and doubts as he responds to a question from Ethel about his writing, admitting that he is writing poems but "none that I am at all satisfied with".
One letter focuses on his thoughts about landscape and how he longs for "once acre of green wood willed with the hum of insects".
This was written three years before his famous poem about nature's beauty, The Lake Isle of Innisfree.
In April 1884, Yeats wrote about one of his earliest verse dramas Time and the Witch Vivien, disclosing it originated at a Christmas fancy dress ball.
On July 18, 1884, he gives a vivid account of the family's move to 10 Ashfield Terrace. "Our new house is better than our old one but dull, from my Howth window I had a view of a wide sea and much heather and at times could say 'there goes a grey gull - let verse be as spontaneous as the flight of a grey full over the bay'."
He goes on, "But here from my window I see a straight wall and by much stretching round the corner, the glimpse of a bush very dim and dusty - a lamentable view for a maker of verses."
He also wrote about some of his friends.
He mentioned CH Oldham, editor of the Dublin Literary Review, who was described by some to be a political radical: "Up to the lips in plots and away in his house on the slopes of the mountains he entertains nihilists and other strange people."
The letters, which sold at a Sotheby's auction in London, had a pre-sale estimate of £12,000 to £18,000 (€13,000-€20,000), but sold for £47,880 (€53,076) to an anonymous buyer.