If you read this poem and think, "I don't get it, anyone could write something like that," then, actually, you've got it. The hardest part about this poem is getting over our preconceptions about poetry. We have to really ask ourselves: what is poetry in the first place?
Williams thinks that poems don't have to be complicated and hard to read. They can be about something that happens everyday, and they can be written in everyday language. As long as something strikes us as true to a human emotion, then it's a poem. Where can you find poetry in your everyday life?