Let him explain what he did. He claims to have taken the old. staid and solemn Latin forms and rhythms and urged them into older but more elaborate Greek lyric stanzas. He also shunned as much as possible the solemn poetry praising battle and empire that Augustus asked for, praising instead the little things he knew and held dear. In that way he was a forerunner of modern populist poets.
So. Instead of armies marching to war he wrote about country life, village and farm. Instead of triumphant generals celebrating victory, friends and acquaintances having a few drinks, joking around, talking about girls. Such a welcome change from Vergil's solemn Aeneid. With irony and self-deprecation he kept his personal life out of the poems. Rather than beg for emotional response, he presented the image; he was the first to claim that a poem must make the hearer "see" what the poet had in mind, the image of the imagination.
After two millenia, Horace still speaks with a voice that resonates today. His images captivate; his forms and metrics intrigue. Now to search for that Epistle, his "Ars Poetica."