In the Oxford Book of English Verse, edited by Christopher Ricks, there are 9 William Wordsworth poems. Old Man Travelling, animal tranquility and decay was selected twice.
Like many of Wordsworth's best poems, this one power is so subtle it is easy to miss it. However, it is poetry and art par excellence.
Since the poem is so short I do not wish to spoil the exhilerating emotional revelation that occurs in a renewed investigation into this poem, so I will merely say that the experience this poem will give you will make you a better person. (Please note that I do not say "may" make you a better person.)