In the “Evening Walk,” composed partly at school, partly in college vacations, he notices how the boughs and leaves of the oak darken and come out when seen against the sunset. “I recollect distinctly,” [Wordsworth] says nearly fifty years afterwards, “the very spot where this first struck me. It was on the way between Hawkshead and Ambleside, and gave me extreme pleasure. The moment was important in my poetical history; for I date from it my consciousness of the infinite variety of natural appearances, which had been unnoticed by the poets of any age or country, so far as I was acquainted with them; and I made a resolution to supply in some degree the deficiency. I could not have been at the time above fourteen years of age.”
It would be hardly too much to say that there is not a single image in his whole works which he had not observed with his own eyes. And perhaps no poet since Homer has introduced into poetry, directly from nature, more facts and images which had not before been noted in books.
—J. C. Shairp, Studies in Poetry and Philosophy (Hurd and Houghton, 1872).