Humility comes through Keats’ letters, though he was also quietly conscious of having something the future would acclaim, even when subjected to scathing reviews (who remembers the reviewers now?).
‘I am three and twenty with little knowledge and middling intellect. It is true that in the height of enthusiasm I have been cheated into some fine passages, but that is nothing.’
Source: John Keats, Selected Letters, ed. Robert Gittings, 8 Mar 1819 (Oxford World Classics, 2002/2009), p. 188